Merge pull request 'write_path stops reporting records it withheld itself as near misses' (#146) from dev into main

Found by verifying the previous fix on live data — the check that fix was
meant to make possible.

    write_path   near_misses.max  0.822    p90 0.7521
                 top_score.min    0.6857   so the bar is at or below this

A "rejection" that outscored every acceptance, and not one outlier: the p90
is above the bar too.

#3739's fix keyed on `suppressed_count`, and I justified its NULL branch as
"null means the caller passed its exclusions INTO the search, so the score
is already post-exclusion". That holds for auto_inject and reuse_slot, both
of which log the RAW search output and do their Python filtering after. It
does not hold for write_path, the one note arm that filters TWICE:
`exclude_ids` takes `seen - pulled_seen` into the search, but the
pulled-and-seen ids stay in the query on purpose — the arm's query doubles
as the resemblance test — and are dropped afterwards in Python. So the row
carries a POST-filter count beside a PRE-filter score.

The suppression column cannot rescue it the way it does for the rule arms.
This arm's count would be PARTIAL — covering the drops made here and not
the ones `exclude_ids` made inside the search — and a partial number under
a name that reads as complete is the substitution this milestone exists to
stop.

So it reports null whenever its own filter removed anything: not measured
on this call, because the bar was not the only thing that turned something
away. Calls that withheld nothing keep reporting, which is most of them.

Both directions are asserted. Without the second test, setting the field to
null unconditionally would pass the first while deleting the measurement
#3670 was built for.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011cPyzNnegXHr5iRMzzy5KJ

.forgejo/workflows/ci.yml

@@ -46,8 +46,6 @@ on:
       - "alembic/**"
       - "alembic.ini"
       - "Dockerfile"
-      - "assets/**"
-      - "fable-mcp/**"
       # The plugin ships straight from this repo — installs fetch it via
       # .claude-plugin/marketplace.json, NOT from the image. So a push here is
       # the release, with no build step in between. Omitting these paths meant
@@ -279,6 +277,21 @@ jobs:
         env:
           UV_PROJECT_ENVIRONMENT: /opt/venv
         run: uv sync --locked --extra dev
+      # Standing answers to the checks carried by rules 81 and 79 — two facts
+      # about THIS runner that conditional rules assert as fact, and that
+      # otherwise need a throwaway job to confirm (#3237). Printing them on
+      # every integration run makes the next rulebook sweep a log read.
+      # Rule 80's evidence is the container listing the next step already
+      # prints. Every command is guarded: a diagnostic that can break the lane
+      # it observes is worse than no diagnostic.
+      - name: Runner facts (rules 79 and 81)
+        run: |
+          echo "--- rule 81: which shell runs a run: step ---"
+          readlink -f /bin/sh || echo "/bin/sh: not a symlink"
+          ps -p $$ -o comm= || true
+          echo "--- rule 79: is a service reachable by its hostname yet? ---"
+          getent hosts postgres \
+            || echo "no — 'postgres' does not resolve; the bridge-IP lookup is still required"
       - name: Integration suite (resolve service IP, migrate, test)
         run: |
           set -eux
@@ -289,8 +302,9 @@ jobs:
           PG_IP=$(docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' "$PG")
           test -n "$PG_IP"
           export DATABASE_URL="postgresql+asyncpg://scribe:ci_integration@${PG_IP}:5432/scribe_test"
-          # Wait for Postgres to accept connections (busybox sh — the runner
-          # default — has no bash /dev/tcp, so use Python).
+          # Wait for Postgres to accept connections. The run: shell is dash
+          # (/bin/sh -> /usr/bin/dash on this Debian-based image, confirmed by
+          # the step above) — no bash /dev/tcp, so use Python.
           /opt/venv/bin/python - "$PG_IP" <<'PY'
           import socket, sys, time
           for _ in range(30):
@@ -327,6 +341,14 @@ jobs:
       packages: write
     steps:
       - uses: actions/checkout@v6
+        with:
+          # Rule 149 asks for this on any job deriving the version NAME. The
+          # name here comes from HEAD's commit TIME, which a depth-1 clone
+          # already has — but the rule states it unconditionally because the
+          # failure it guards is silent (a too-low value, every lane green),
+          # and a later change to how the name is derived would inherit the
+          # landmine rather than the guard.
+          fetch-depth: 0
 
       - name: Generate image tags and version
         id: tags
@@ -339,7 +361,27 @@ jobs:
         # the runner log on commit 2a374d9.
         run: |
           TAGS="${{ env.IMAGE }}:${{ github.sha }}"
-          BUILD_VERSION="dev"
+
+          # THREE VALUES, NEVER FOLDED TOGETHER (rule 149). Until 2026-08-31
+          # BUILD_VERSION was the CHANNEL — "dev" / "main" / the tag — so the
+          # image self-reported {"version":"main"}, a channel name where a
+          # build identifier belongs. That cost a debugging session: with the
+          # deploy misbehaving, nothing on the running instance could say
+          # which commit was serving it.
+
+          # 1. ORDERING KEY — BUILD time, monotonic by construction. Minutes
+          #    since 2020-01-01. Never a commit count (not monotonic across
+          #    branches) and never commit time (goes DOWN when an older
+          #    commit is rebuilt).
+          BUILD_KEY=$(( ( $(date -u +%s) - 1577836800 ) / 60 ))
+
+          # 2. NAME — COMMIT time, so the same source reports the same string
+          #    on every lane and the channel is the only thing that differs.
+          COMMIT_TS=$(git log --format=%ct -1 HEAD)
+          BUILD_NAME=$(date -u -d "@$COMMIT_TS" +%Y.%m.%d.%H%M)
+
+          # 3. CHANNEL — its own value. Never a suffix, never a segment.
+          CHANNEL="dev"
           case "${{ github.ref }}" in
             refs/heads/dev)
               TAGS="$TAGS,${{ env.IMAGE }}:dev"
@@ -348,15 +390,17 @@ jobs:
               # main IS the production line: publish :latest (plus the :<sha>
               # set above). No separate :main tag.
               TAGS="$TAGS,${{ env.IMAGE }}:latest"
-              BUILD_VERSION="main"
+              CHANNEL="stable"
               ;;
             refs/tags/*)
               TAGS="$TAGS,${{ env.IMAGE }}:latest,${{ env.IMAGE }}:${{ github.ref_name }}"
-              BUILD_VERSION="${{ github.ref_name }}"
+              CHANNEL="stable"
               ;;
           esac
           echo "value=$TAGS" >> $GITHUB_OUTPUT
-          echo "build_version=$BUILD_VERSION" >> $GITHUB_OUTPUT
+          echo "build_name=$BUILD_NAME" >> $GITHUB_OUTPUT
+          echo "build_key=$BUILD_KEY" >> $GITHUB_OUTPUT
+          echo "channel=$CHANNEL" >> $GITHUB_OUTPUT
 
       - name: Free disk space
         # Self-hosted runner housekeeping. Two-step cleanup:
@@ -386,7 +430,15 @@ jobs:
           push: true
           provenance: false
           tags: ${{ steps.tags.outputs.value }}
-          build-args: BUILD_VERSION=${{ steps.tags.outputs.build_version }}
+          # All three, plus the commit — rule 145: the registry's identity for
+          # a build (:<sha>) and the artifact's identity for itself must
+          # agree, and they can only be checked against each other if the
+          # artifact says which commit it is.
+          build-args: |
+            BUILD_VERSION=${{ steps.tags.outputs.build_name }}
+            BUILD_KEY=${{ steps.tags.outputs.build_key }}
+            BUILD_CHANNEL=${{ steps.tags.outputs.channel }}
+            BUILD_COMMIT=${{ github.sha }}
           # Registry-backed layer cache. Pull from :cache to prime
           # BuildKit, push updated layers back to :cache so the next
           # build starts warm even if the runner's local cache was

Dockerfile

@@ -41,10 +41,29 @@ COPY alembic/ alembic/
 # Ensure Python finds the source tree (where static files live) before site-packages
 ENV PYTHONPATH=/app/src
 
-# Version is injected at build time via --build-arg BUILD_VERSION=YY.MM.DD.N
-# Falls back to "dev" for local / untagged builds
+# THREE VALUES, NEVER FOLDED TOGETHER (rule 149), plus the commit.
+#
+# BUILD_VERSION is the NAME (YYYY.MM.DD.HHMM, from COMMIT time) — the same
+#   string on every lane for the same source, so it answers "is this the same
+#   code?" rather than "which lane built it?".
+# BUILD_KEY is the ORDERING KEY (minutes since 2020-01-01, from BUILD time) —
+#   the only value anything may compare to decide what is newer.
+# BUILD_CHANNEL is its own field. Never a suffix, never a segment of the name.
+# BUILD_COMMIT lets the artifact's self-report be checked against the :<sha>
+#   it was published under (rule 145).
+#
+# Each defaults to empty rather than to a placeholder, EXCEPT the name: a
+# local build genuinely has no ordering key or channel, and the endpoint says
+# so by omitting them. Inventing values would make a local image claim a
+# position in an update order it is not part of.
 ARG BUILD_VERSION=dev
+ARG BUILD_KEY=
+ARG BUILD_CHANNEL=
+ARG BUILD_COMMIT=
 ENV APP_VERSION=$BUILD_VERSION
+ENV APP_BUILD_KEY=$BUILD_KEY
+ENV APP_CHANNEL=$BUILD_CHANNEL
+ENV APP_COMMIT=$BUILD_COMMIT
 
 EXPOSE 5000
 CMD ["sh", "-c", "alembic upgrade head && hypercorn 'scribe.app:create_app()' --bind 0.0.0.0:5000 --keep-alive 600"]

Makefile

@@ -1,4 +1,4 @@
-.PHONY: build up down logs health migrate lint typecheck test fmt
+.PHONY: build up down logs health migrate lint typecheck test fmt mint-plugin
 
 # --- Docker ---
 
@@ -36,3 +36,12 @@ test:
 
 # Run all checks in one shot (mirrors what CI does)
 check: lint typecheck test
+
+# --- Plugin ---
+
+# Run this after changing anything under plugin/ or .claude-plugin/, BEFORE
+# committing. The plugin ships straight from git with no build step, so its
+# version is minted here rather than stamped by CI; the lane fails if you
+# forget, but this is what makes remembering cheap.
+mint-plugin:
+	python3 scripts/mint_plugin_version.py

alembic/versions/0094_rule_usage_events.py

@@ -0,0 +1,86 @@
+"""add rule_usage_events — was a surfaced rule ever read? (milestone 333 step 1)
+
+Revision ID: 0094
+Revises: 0093
+Create Date: 2026-09-02
+
+The sibling `note_usage_events` has had since 0071, and the third rule-side
+table to arrive after `rule_embeddings` and `rule_versions` — each one added
+because the rule side kept inheriting machinery built for notes and getting
+the weaker version of it.
+
+WHAT IT MEASURES. The write-path standing-rule arm is the only retrieval
+surface in Scribe whose usefulness cannot be observed, and — not coincidentally
+— the only one that has never declined to fire. Over 30 days it took 296 calls,
+returned something on every one, and cleared its threshold 100% of the time,
+while every other surface declines most of the time (#3311). That is either a
+perfectly tuned surface or a bar it cannot fail to clear, and `retrieval_logs`
+cannot tell them apart: it records what the ranker scored, never whether the
+hint was any use.
+
+WHY NOT A rule_id COLUMN ON note_usage_events. The row shares no note-specific
+fields and the aggregate readout is the same shape, which is the strongest case
+for sharing that note #3163 admits. What decides against it is identity at
+RESTORE: `note_usage_events`'s importer maps `note_id` through `note_id_map`
+and drops what does not resolve. A rule id parked in that column would come
+back from a backup silently reattached to whatever note took that number —
+telemetry not merely lost but wrong, and wrong in a way nothing downstream
+could detect. `rule_versions` made the same call for the same reason.
+
+FK-free on `rule_id` and `user_id`, matching note_usage_events, retrieval_logs
+and app_logs — and deliberately unlike `rule_versions`, which does carry FKs.
+The difference is what the row is for: a version belongs to a rule's history
+and dies with it; telemetry outlives the row it describes. Deleting a rule must
+not erase the evidence that it was surfaced forty times and opened never, since
+that evidence is exactly the case for having deleted it.
+
+No CHECK on `event`, matching the note twin. Rule 36 governs adding a value to
+a column that is already gated; it does not require gating one that never was,
+and a two-member enum whose members are written by two functions in one module
+is not where that discipline earns its cost.
+
+Downgrade drops the table outright. The data is purely observational — nothing
+reads it for correctness, so losing it costs history and no behaviour.
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+revision = "0094"
+down_revision = "0093"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.create_table(
+        "rule_usage_events",
+        # BigInteger throughout where the note twin uses Integer: rules.id is
+        # BigInteger, so rule_id must be, and a high-churn append-only table is
+        # a poor place to discover an id ceiling.
+        sa.Column("id", sa.BigInteger(), primary_key=True),
+        sa.Column(
+            "created_at",
+            sa.DateTime(timezone=True),
+            nullable=False,
+            server_default=sa.text("now()"),
+        ),
+        sa.Column("user_id", sa.BigInteger(), nullable=True),
+        sa.Column("rule_id", sa.BigInteger(), nullable=False),
+        sa.Column("event", sa.Text(), nullable=False),
+        sa.Column("source", sa.Text(), nullable=False),
+    )
+    # Every readout is "these rule ids, split by event", so the composite is the
+    # one that actually gets used; the others serve pruning and per-user views.
+    op.create_index(
+        "ix_rule_usage_rule_event", "rule_usage_events", ["rule_id", "event"]
+    )
+    op.create_index("ix_rule_usage_created_at", "rule_usage_events", ["created_at"])
+    op.create_index("ix_rule_usage_user_id", "rule_usage_events", ["user_id"])
+
+
+def downgrade() -> None:
+    op.drop_index("ix_rule_usage_user_id", table_name="rule_usage_events")
+    op.drop_index("ix_rule_usage_created_at", table_name="rule_usage_events")
+    op.drop_index("ix_rule_usage_rule_event", table_name="rule_usage_events")
+    op.drop_table("rule_usage_events")

alembic/versions/0095_retrieval_log_suppressed_count.py

@@ -0,0 +1,52 @@
+"""add retrieval_logs.suppressed_count — tell a ranker decline from a repeat (#3497)
+
+Revision ID: 0095
+Revises: 0094
+Create Date: 2026-09-03
+
+`result_count == 0` has always meant "this surface said nothing", which is the
+right number for "was the hint any use" and the wrong one for tuning a
+threshold. It folds together two unrelated events:
+
+  - the ranker found nothing above the bar — the ONLY evidence a threshold is
+    set too high; and
+  - the ranker found something the session had already been shown — a decline
+    that says nothing whatever about the bar.
+
+The rule arms filter in Python after the search, so they can count the second
+kind exactly. The note arms pass `exclude_ids` INTO semantic_search_notes, so
+the dropped rows never come back and there is nothing to count.
+
+NULLABLE, AND THE NULL IS THE POINT. A surface that does not measure
+suppression stores NULL, not 0, and the readout renders it as "not measured"
+rather than "none". Defaulting to 0 would make an unmeasured surface look like
+a perfectly clean one — the exact substitution of an artifact for a
+measurement that #3311 made and that #3497 exists to correct. Doing it again,
+in the migration that fixes it, would be its own small joke.
+
+No backfill for the same reason: existing rows genuinely do not know, and
+saying so is the honest state. `retrieval_logs` is not restored from backup,
+so no importer changes.
+
+Downgrade drops the column. Purely observational — nothing reads it for
+correctness.
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+revision = "0095"
+down_revision = "0094"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.add_column(
+        "retrieval_logs",
+        sa.Column("suppressed_count", sa.Integer(), nullable=True),
+    )
+
+
+def downgrade() -> None:
+    op.drop_column("retrieval_logs", "suppressed_count")

alembic/versions/0096_retrieval_log_best_available_score.py

@@ -0,0 +1,62 @@
+"""add retrieval_logs.best_available_score — the score the bar rejected (#3670)
+
+Revision ID: 0096
+Revises: 0095
+Create Date: 2026-09-08
+
+`cleared_threshold` was documented as the number to read FIRST — "a surface
+that clears its bar on nearly every call is either well-tuned or too loose,
+and p10 says which". It was never a measurement. The search applies the
+threshold before returning, so every returned result cleared the bar by
+construction and a call with no results has no `top_score` to compare:
+the condition is true exactly when `result_count > 0`.
+
+`zero_result_calls + cleared_threshold == calls` held on all nineteen
+source/window readings ever taken. It was `calls - zero_result_calls`
+wearing a name that promised a second opinion, and a reading procedure was
+built on top of it that asked the reader to compare a number against itself.
+
+THE MISSING NUMBER, and the reason this is a column rather than a deletion.
+The question the table exists to answer is "is the bar in the right place",
+and that question is only answerable from the calls that returned NOTHING:
+how close did the best rejected candidate come? A bar at 0.72 turning away
+a stream of 0.71s is set too high by a hair. A bar turning away 0.30s is
+doing its job. Those two are indistinguishable today — both render as a
+zero-result call — and no arrangement of the existing columns separates
+them, because the losing score is discarded inside the search.
+
+So the searches now rank without the bar and apply it in Python, which
+costs nothing (the rows were already ordered by distance, and the qualifying
+set is provably identical — above-threshold rows sort first), and the best
+score seen becomes observable.
+
+NULLABLE, AND UNBACKFILLED, for the reason 0095 spells out: a row written
+before this shipped genuinely does not know what its best rejected candidate
+scored, and saying so is the honest state. A 0.0 default would read as "the
+corpus had nothing remotely relevant" — an artifact standing in for a
+measurement, which is the whole defect this milestone corrects.
+
+`retrieval_logs` is not restored from backup, so no importer changes.
+
+Downgrade drops the column. Purely observational — nothing reads it for
+correctness.
+"""
+from alembic import op
+import sqlalchemy as sa
+
+
+revision = "0096"
+down_revision = "0095"
+branch_labels = None
+depends_on = None
+
+
+def upgrade() -> None:
+    op.add_column(
+        "retrieval_logs",
+        sa.Column("best_available_score", sa.Float(), nullable=True),
+    )
+
+
+def downgrade() -> None:
+    op.drop_column("retrieval_logs", "best_available_score")

frontend/src/App.vue

@@ -7,12 +7,20 @@ import { useTheme } from "@/composables/useTheme";
 import { useShortcuts } from "@/composables/useShortcuts";
 import { useAuthStore } from "@/stores/auth";
 import { useSettingsStore } from "@/stores/settings";
-import { apiGet, apiPut } from "@/api/client";
+import { apiPut } from "@/api/client";
+import { fetchVersion } from "@/api/version";
 
 useTheme();
 
 const router = useRouter();
-const appVersion = ref("dev");
+// THREE states, not two (#3127 checklist 12). `null` is "not answered yet" and
+// renders nothing; a string renders; `appVersionFailed` renders its own thing.
+// This used to default to the literal "dev" and swallow the error, which meant
+// an instance that could not answer was indistinguishable from a local build
+// that genuinely reports "dev" — a blank standing in for `unknown`, in the one
+// readout whose whole job is to say what is running.
+const appVersion = ref<string | null>(null);
+const appVersionFailed = ref(false);
 const authStore = useAuthStore();
 const settingsStore = useSettingsStore();
 const { showShortcuts, toggleShortcuts, closeShortcuts } = useShortcuts();
@@ -119,10 +127,12 @@ onMounted(async () => {
     startAppServices();
   }
   try {
-    const data = await apiGet<{ version: string }>("/api/version");
-    appVersion.value = data.version;
+    appVersion.value = (await fetchVersion()).version;
   } catch {
-    // silent — version display is non-critical
+    // Not silent any more: the footer says it could not find out, rather than
+    // showing a version it never received. The full readout (version, channel,
+    // commit, build) lives in Settings → Config.
+    appVersionFailed.value = true;
   }
 });
 
@@ -151,7 +161,10 @@ onUnmounted(() => {
       <div id="main-content" class="app-content">
         <router-view />
       </div>
-      <footer class="app-footer">v{{ appVersion }}</footer>
+      <footer class="app-footer">
+        <span v-if="appVersion">v{{ appVersion }}</span>
+        <span v-else-if="appVersionFailed">version unknown</span>
+      </footer>
     </div>
 
     <!-- Keyboard shortcuts overlay -->

frontend/src/api/client.ts

@@ -52,41 +52,121 @@ export function apiErrorMessage(e: unknown, fallback: string): string {
   return fallback;
 }
 
-export async function apiGet<T>(path: string): Promise<T> {
-  const res = await fetch(path);
+/**
+ * How long an ordinary JSON call may wait before it is declared failed.
+ *
+ * Rule 156: a wait with no deadline is a bug. `fetch`'s own default is to wait
+ * as long as the browser will, which is not a deadline — it is the absence of
+ * one, and it renders as a spinner that never resolves. There is no state a
+ * surface can show for "pending forever" that is not a lie.
+ *
+ * 30s is chosen to be longer than anything healthy: it has to clear a cold
+ * embedding call and a list view under connection-pool contention (#2384 had
+ * /api/projects fanning 25 concurrent sessions at a 15-connection pool), so
+ * tripping it means something is genuinely wrong rather than merely busy. Slow
+ * BY DESIGN is a different case and passes its own value — see the callers in
+ * SettingsView that do.
+ */
+const DEFAULT_TIMEOUT_MS = 30_000;
+
+/** HTTP 408. Not a status any Scribe route returns, so it unambiguously means
+ *  "the client gave up" rather than anything the server said. */
+const CLIENT_TIMEOUT_STATUS = 408;
+
+/**
+ * How long a STREAM may take to answer with its headers.
+ *
+ * Streams are the one case a wall-clock deadline would break: a long-lived SSE
+ * connection is *supposed* to stay open, and `AbortSignal.timeout` would kill
+ * it mid-flight along with the body. But that does not exempt them from rule
+ * 156 — it relocates the deadline. Two different waits are involved:
+ *
+ *   connect — the server answering with headers. CAN fail to answer, so it
+ *             carries this deadline, cleared the moment headers arrive.
+ *   stream  — the body, open indefinitely on purpose. Its failure mode is
+ *             going quiet, which a timeout cannot tell from being idle; that
+ *             is what reconnection and Last-Event-ID are for, not this.
+ *
+ * Reading the connect as exempt because "the stream is long-lived" is the easy
+ * mistake here, and it leaves an unreachable server looking like a quiet one.
+ */
+const STREAM_CONNECT_TIMEOUT_MS = 15_000;
+
+/**
+ * A signal that aborts if headers do not arrive in time, plus the `settle` to
+ * call once they do. After `settle()` the returned signal never fires, so the
+ * stream body runs unbounded — which is the intent.
+ */
+function connectDeadline(base: AbortSignal): { signal: AbortSignal; settle: () => void } {
+  const gate = new AbortController();
+  const timer = setTimeout(
+    () => gate.abort(new DOMException("stream did not connect in time", "TimeoutError")),
+    STREAM_CONNECT_TIMEOUT_MS,
+  );
+  return {
+    signal: AbortSignal.any([base, gate.signal]),
+    settle: () => clearTimeout(timer),
+  };
+}
+
+export interface RequestOpts {
+  /** Override the deadline. Pass one when the call is slow BY DESIGN. */
+  timeoutMs?: number;
+}
+
+/**
+ * The one place a request is actually made — every verb below goes through
+ * here, so the deadline cannot be forgotten by adding a sixth.
+ *
+ * EXPIRY SURFACES AS AN `ApiError`, which is rule 156's second half: the
+ * failure has to arrive in the shape the caller already handles. A bare
+ * `DOMException: TimeoutError` would reach `apiErrorMessage(e, fallback)` as
+ * an object with no `body`, so every catch site in the app would report its
+ * generic fallback and the timeout would be invisible in the very situation it
+ * exists to expose. Rethrowing as `ApiError` means ~330 existing call sites
+ * report it correctly without being touched.
+ *
+ * Only a TIMEOUT is converted. A deliberate cancellation aborts with
+ * `AbortError` and is left alone — a caller that cancelled its own request
+ * does not want it reported as a server failure.
+ */
+async function request<T>(path: string, init: RequestInit, opts?: RequestOpts): Promise<T> {
+  const timeoutMs = opts?.timeoutMs ?? DEFAULT_TIMEOUT_MS;
+  let res: Response;
+  try {
+    res = await fetch(path, { ...init, signal: AbortSignal.timeout(timeoutMs) });
+  } catch (e) {
+    if (e instanceof DOMException && e.name === "TimeoutError") {
+      throw new ApiError(CLIENT_TIMEOUT_STATUS, {
+        error: `The server did not answer within ${Math.round(timeoutMs / 1000)}s.`,
+      });
+    }
+    throw e;
+  }
   return handleResponse<T>(res, path);
 }
 
-export async function apiPost<T>(path: string, body: unknown): Promise<T> {
-  const res = await fetch(path, {
-    method: "POST",
-    headers: { "Content-Type": "application/json" },
-    body: JSON.stringify(body),
-  });
-  return handleResponse<T>(res, path);
+/** JSON body headers — the three write verbs sent an identical literal each. */
+const JSON_HEADERS = { "Content-Type": "application/json" };
+
+export function apiGet<T>(path: string, opts?: RequestOpts): Promise<T> {
+  return request<T>(path, {}, opts);
 }
 
-export async function apiPut<T>(path: string, body: unknown): Promise<T> {
-  const res = await fetch(path, {
-    method: "PUT",
-    headers: { "Content-Type": "application/json" },
-    body: JSON.stringify(body),
-  });
-  return handleResponse<T>(res, path);
+export function apiPost<T>(path: string, body: unknown, opts?: RequestOpts): Promise<T> {
+  return request<T>(path, { method: "POST", headers: JSON_HEADERS, body: JSON.stringify(body) }, opts);
 }
 
-export async function apiPatch<T>(path: string, body: unknown): Promise<T> {
-  const res = await fetch(path, {
-    method: "PATCH",
-    headers: { "Content-Type": "application/json" },
-    body: JSON.stringify(body),
-  });
-  return handleResponse<T>(res, path);
+export function apiPut<T>(path: string, body: unknown, opts?: RequestOpts): Promise<T> {
+  return request<T>(path, { method: "PUT", headers: JSON_HEADERS, body: JSON.stringify(body) }, opts);
 }
 
-export async function apiDelete(path: string): Promise<void> {
-  const res = await fetch(path, { method: "DELETE" });
-  return handleResponse<void>(res, path);
+export function apiPatch<T>(path: string, body: unknown, opts?: RequestOpts): Promise<T> {
+  return request<T>(path, { method: "PATCH", headers: JSON_HEADERS, body: JSON.stringify(body) }, opts);
+}
+
+export function apiDelete(path: string, opts?: RequestOpts): Promise<void> {
+  return request<void>(path, { method: "DELETE" }, opts);
 }
 
 // ---------------------------------------------------------------------------
@@ -221,7 +301,14 @@ export function apiSSEStream(
   }
 
   const done = (async () => {
-    const res = await fetch(path, { headers, signal: combinedSignal });
+    // Bounded connect, unbounded stream — see STREAM_CONNECT_TIMEOUT_MS.
+    const connect = connectDeadline(combinedSignal);
+    let res: Response;
+    try {
+      res = await fetch(path, { headers, signal: connect.signal });
+    } finally {
+      connect.settle();
+    }
     if (!res.ok) {
       let body: Record<string, unknown> = {};
       try {
@@ -318,11 +405,19 @@ export async function apiStreamPost(
   body: unknown,
   onChunk: (data: Record<string, unknown>) => void
 ): Promise<void> {
-  const res = await fetch(path, {
-    method: "POST",
-    headers: { "Content-Type": "application/json" },
-    body: JSON.stringify(body),
-  });
+  // Bounded connect, unbounded stream — see STREAM_CONNECT_TIMEOUT_MS.
+  const connect = connectDeadline(new AbortController().signal);
+  let res: Response;
+  try {
+    res = await fetch(path, {
+      method: "POST",
+      headers: JSON_HEADERS,
+      body: JSON.stringify(body),
+      signal: connect.signal,
+    });
+  } finally {
+    connect.settle();
+  }
   if (!res.ok) {
     let errBody: Record<string, unknown> = {};
     try {

frontend/src/api/rulebooks.ts

@@ -1,3 +1,5 @@
+import type { RecordUsage } from "@/types/usage";
+
 import { apiGet, apiPost, apiPatch, apiDelete } from "@/api/client";
 
 /** How a rule reaches a session (milestone 307). */
@@ -96,6 +98,13 @@ export interface RuleHeader {
    * A date (YYYY-MM-DD), or the literal "never".
    */
   last_verified?: string;
+  /**
+   * Surfaced-vs-opened counts from `rule_usage_events` (milestone 333).
+   * Zero-filled by the list route, so a rule predating the table reads as
+   * "never surfaced" rather than as a missing field — which for a while is
+   * every rule on every install.
+   */
+  usage?: RecordUsage;
 }
 
 export interface ApplicableRules {

frontend/src/api/snippets.ts

@@ -1,3 +1,5 @@
+import type { RecordUsage } from "@/types/usage";
+
 import { apiGet, apiPost, apiPatch, apiDelete } from "@/api/client";
 
 /** One canonical location of a reusable thing. A snippet that unifies several
@@ -50,15 +52,11 @@ export interface Snippet {
   owner?: string | null;
 }
 
-/** How often a record was put in front of an agent versus actually opened.
- *  A high `surfaced_count` with `pull_count: 0` is dead weight — it occupies a
- *  slot in every future auto-inject menu while never being used. */
-export interface SnippetUsage {
-  surfaced_count: number;
-  pull_count: number;
-  last_surfaced_at: string | null;
-  last_pulled_at: string | null;
-}
+/** Kept as a name because every consumer here says "snippet usage" — but it IS
+ *  the shared shape, since rules answer the same question off their own table
+ *  (milestone 333). The reasoning lives on `RecordUsage`; duplicating the four
+ *  fields here is how the two drift. */
+export type SnippetUsage = RecordUsage;
 
 /** Result of the last drift check — does the recorded location and code still
  *  match source? The check runs agent-side (Scribe has no checkout); this is the

frontend/src/api/version.ts

@@ -0,0 +1,44 @@
+import { apiGet } from "./client";
+
+/**
+ * What `/api/version` answers — the client's half of `build_version_payload`
+ * (`src/scribe/routes/api.py`), which is where the reasoning for the shape is
+ * written down.
+ *
+ * EVERY FIELD BUT `version` IS OPTIONAL, and an absent one means "this build
+ * does not know", not "empty". A local build has no ordering key and no
+ * channel, and the server says so by omitting the keys rather than sending
+ * `""` — emitting a placeholder would let it claim a position in an update
+ * order it is not part of.
+ *
+ * So a renderer must read ABSENCE, never falsiness. `build` is a number and
+ * `0` is a legitimate ordering key, so `v.build || "unknown"` would report a
+ * real value as unknown; `v.build ?? "unknown"` is the correct form.
+ */
+export interface VersionPayload {
+  /** The NAME — `YYYY.MM.DD.HHMM` from commit time. Answers "is this the same code?" */
+  version: string;
+  /** The ORDERING KEY — minutes since 2020-01-01, from build time. Absent on a local build. */
+  build?: number;
+  /** `dev` / `main` / a tag. Its own field, never folded into the name. */
+  channel?: string;
+  /** The commit the artifact was published under, so its claim can be checked against the registry. */
+  commit?: string;
+}
+
+/**
+ * SHORTER than the client's 30s default, deliberately.
+ *
+ * This readout answers "what is running?" during an incident, which is exactly
+ * when the server may be the thing that is unwell — and it is one static field
+ * off a route that does no work, so a healthy instance answers it immediately.
+ * Waiting the full default before saying so would leave a person staring at
+ * "still loading" for half a minute in the moment they are trying to find out
+ * whether the instance is alive at all. Eight seconds clears a slow-but-alive
+ * instance and tells them something quickly when it is not.
+ */
+const VERSION_TIMEOUT_MS = 8000;
+
+export function fetchVersion(): Promise<VersionPayload> {
+  return apiGet<VersionPayload>("/api/version", { timeoutMs: VERSION_TIMEOUT_MS });
+}

frontend/src/assets/components.css

@@ -351,3 +351,29 @@
 
 .required { color: var(--fs-error); }
 .field-hint { margin: 0.3rem 0 0; font-size: 0.8rem; color: var(--fs-text-tertiary); }
+
+/* --- usage badge ----------------------------------------------------------
+   "surfaced N×, opened M×" on a list row, for any record kind the retrieval
+   surfaces can choose: snippets and notes from note_usage_events, rules from
+   rule_usage_events. Promoted here from SnippetListView's scoped block when
+   the rule list needed the same chip (milestone 333 step 5) — a second scoped
+   copy is how the ninth duplicated CSS family starts (#3207).
+
+   Geometry and colour only. A view keeps its own spacing as a scoped
+   remainder, the way it does for every other recipe in this file. */
+.usage-tag {
+  font-size: 0.7rem;
+  padding: 0.1rem 0.4rem;
+  border-radius: 4px;
+  white-space: nowrap;
+  font-variant-numeric: tabular-nums;
+  background: color-mix(in srgb, var(--fs-text-tertiary) 15%, transparent);
+  color: var(--fs-text-tertiary-fg);
+}
+
+/* Dead weight is a nudge, not an error — it warns in the warning colour rather
+   than the danger one, because the record isn't broken, just unearned. */
+.usage-tag.usage-dead {
+  background: color-mix(in srgb, var(--fs-warning) 18%, transparent);
+  color: var(--fs-warning-fg);
+}

frontend/src/components/UsageBadge.vue

@@ -0,0 +1,62 @@
+<script setup lang="ts">
+/**
+ * "N/M used" on a list row — surfaced vs opened, for any record kind.
+ *
+ * Extracted from SnippetListView when the rule list needed the same chip
+ * (milestone 333 step 5). The counts read identically for both; what differs
+ * is the ADVICE, which is why that is a prop. A snippet surfaced repeatedly
+ * and never opened should probably go; a rule in the same position may simply
+ * have a `when_to_apply` that fires on the wrong thing, and telling an
+ * operator to delete it would be the wrong nudge half the time.
+ */
+import type { RecordUsage } from "@/types/usage";
+
+const props = defineProps<{
+  usage?: RecordUsage | null;
+  /** What to suggest when this record looks like dead weight. Appended to the
+   *  tooltip; kind-specific, because the remedies are. */
+  deadWeightAdvice: string;
+  /** What the record is called in the tooltip's own sentence. */
+  noun?: string;
+}>();
+
+/** Offered repeatedly and never opened. Three rather than one because one or
+ *  two surfacings is noise — the record may simply not have come up in a
+ *  relevant context yet. */
+const isDeadWeight = () =>
+  !!props.usage && props.usage.pull_count === 0 && props.usage.surfaced_count >= 3;
+
+/** "" renders nothing. A record nobody has surfaced yet gets no badge at all:
+ *  "0/0" would read as a verdict when it is an absence of evidence — and on a
+ *  freshly-migrated install that is every row. */
+const label = () => {
+  const u = props.usage;
+  if (!u || u.surfaced_count === 0) return "";
+  return `${u.pull_count}/${u.surfaced_count} used`;
+};
+
+const title = () => {
+  const u = props.usage;
+  if (!u) return "";
+  const last = u.last_pulled_at
+    ? `Last opened ${new Date(u.last_pulled_at).toLocaleDateString()}.`
+    : "Never opened.";
+  const verdict = isDeadWeight() ? ` ${props.deadWeightAdvice}` : "";
+  return (
+    `Surfaced to an agent ${u.surfaced_count}×, opened in full ` +
+    `${u.pull_count}×. ${last}${verdict}`
+  );
+};
+</script>
+
+<template>
+  <span
+    v-if="label()"
+    class="usage-tag"
+    :class="{ 'usage-dead': isDeadWeight() }"
+    :title="title()"
+  >{{ label() }}</span>
+</template>
+
+<!-- The look lives in components.css (canon). Nothing scoped here on purpose:
+     a view that needs different spacing keeps that as its own remainder. -->

frontend/src/components/rules/RuleListPane.vue

@@ -1,5 +1,16 @@
 <script setup lang="ts">
 import type { RuleHeader } from "@/api/rulebooks";
+import UsageBadge from "@/components/UsageBadge.vue";
+
+/** The dead-weight nudge for a RULE — two remedies, not one, which is the
+ *  whole reason this advice is per-kind. A snippet nobody opens should
+ *  probably go. A rule nobody opens may be perfectly good and simply firing on
+ *  the wrong thing, so "delete it" would be the wrong nudge half the time and
+ *  the operator has to be the one who picks. */
+const RULE_DEAD_WEIGHT =
+  "Kept arriving without being read. Either its trigger fires on the wrong " +
+  "work — reword “when to apply” so it says when — or it is not wanted here. " +
+  "Until one or the other, it takes a slot in every write it matches.";
 
 defineProps<{ topicId: number; rules: RuleHeader[] }>();
 const emit = defineEmits<{
@@ -28,6 +39,7 @@ const emit = defineEmits<{
               ? 'Asserts a fact nobody has confirmed yet'
               : `Check last passed ${r.last_verified}`"
           >{{ r.last_verified === "never" ? "unverified" : `checked ${r.last_verified}` }}</span>
+          <UsageBadge :usage="r.usage" :dead-weight-advice="RULE_DEAD_WEIGHT" />
         </div>
         <div class="statement">{{ r.statement }}</div>
         <div v-if="r.when_to_apply || r.updated_at" class="meta">

frontend/src/types/usage.ts

@@ -0,0 +1,23 @@
+/**
+ * How often a record was put in front of an agent, and how often one then
+ * opened it in full.
+ *
+ * One shape for every record kind the retrieval surfaces can choose. Snippets
+ * and notes are counted in `note_usage_events`; rules in `rule_usage_events`,
+ * which is a separate table because a note id and a rule id are different
+ * namespaces resolved through different maps at restore (milestone 333). The
+ * TABLES are separate for that reason; the READOUT is the same question, so
+ * the client type is one.
+ *
+ * A high `surfaced_count` with `pull_count: 0` is dead weight — it occupies a
+ * slot in every future menu while never being used. What to DO about that
+ * differs by kind, which is why the advice is a prop on the badge rather than
+ * a property of this type: a snippet nobody opens should probably be deleted,
+ * while a rule nobody opens may just be mis-triggered.
+ */
+export interface RecordUsage {
+  surfaced_count: number;
+  pull_count: number;
+  last_surfaced_at: string | null;
+  last_pulled_at: string | null;
+}

frontend/src/views/SettingsView.vue

@@ -9,6 +9,7 @@ import type { User } from "@/types/auth";
 import PaginationBar from "@/components/PaginationBar.vue";
 import TagInput from "@/components/TagInput.vue";
 import { fmtDate, fmtLogStamp } from "@/utils/dateFormat";
+import { fetchVersion, type VersionPayload } from "@/api/version";
 
 const store = useSettingsStore();
 const authStore = useAuthStore();
@@ -85,6 +86,7 @@ const kbWritePathEnabled = ref(true);
 // code embeddings sit on a much higher similarity floor than prose, so 0.55 let
 // unrelated code through (#2223). Shares top-k, not the threshold.
 const kbWritePathThreshold = ref("0.68");
+const kbRuleHintThreshold = ref("0.72");
 // Near-duplicate report floors, one per record kind (services/dedup.py).
 // Snippets are single-chunk, so their floor sits below the 0.90 write-time
 // gate and catches what it lets through. Notes/tasks are scored at chunk
@@ -147,12 +149,17 @@ async function saveKbInject() {
   // Same `|| default` reasoning: falling back to 0 would surface every
   // snippet in the corpus on every edit, which is the failure this knob fixes.
   const wpT = Math.min(1, Math.max(0, Number(kbWritePathThreshold.value) || 0.68));
+  // Same `|| default` reasoning again, and it bites harder here: a rule hint
+  // fires on every write, so a fallback of 0 would attach a standing rule to
+  // every edit in the session.
+  const rhT = Math.min(1, Math.max(0, Number(kbRuleHintThreshold.value) || 0.72));
   kbInjectThreshold.value = String(t);
   kbInjectTopK.value = String(k);
   kbDupThresholdSnippet.value = String(dupSnip);
   kbDupThresholdNote.value = String(dupNote);
   kbDupThresholdTask.value = String(dupTask);
   kbWritePathThreshold.value = String(wpT);
+  kbRuleHintThreshold.value = String(rhT);
   savingKbInject.value = true;
   kbInjectSaved.value = false;
   try {
@@ -165,6 +172,10 @@ async function saveKbInject() {
       // measurements that split them.
       kb_writepath_enabled: kbWritePathEnabled.value ? 'true' : 'false',
       kb_writepath_threshold: String(wpT),
+      // A THIRD corpus with a third bar — see RULEHINT_DEFAULT_THRESHOLD
+      // in services/plugin_context.py for why rules cannot share the
+      // code threshold any more than code could share the prose one.
+      kb_rulehint_threshold: String(rhT),
       kb_duplicate_threshold_snippet: String(dupSnip),
       kb_duplicate_threshold_note: String(dupNote),
       kb_duplicate_threshold_task: String(dupTask),
@@ -187,7 +198,47 @@ const changingPassword = ref(false);
 const invalidatingSessions = ref(false);
 const exporting = ref(false);
 const restoring = ref(false);
-const appVersion = ref('dev');
+// Backup, export and restore walk the whole store, so they are slow BY DESIGN
+// and the client's ordinary 30s default would cut them off mid-work. They are
+// still bounded: rule 156 asks for a deadline, not a short one, and "no ceiling
+// at all" is what leaves a restore that died server-side spinning forever.
+const BULK_TRANSFER_TIMEOUT_MS = 10 * 60 * 1000;
+
+function bulkDeadline(): AbortSignal {
+  return AbortSignal.timeout(BULK_TRANSFER_TIMEOUT_MS);
+}
+
+// ── What's running (#3127 checklist 12) ─────────────────────────────────
+// Three states kept apart, because collapsing any two of them is the defect
+// this readout exists to remove: `null` + no error = not asked yet (the Config
+// tab has not been opened); a payload = answered, with each ABSENT field shown
+// as "unknown"; `versionError` = the fetch itself failed, which is its own
+// thing and must never render as a blank or as a plausible-looking value.
+const versionInfo = ref<VersionPayload | null>(null);
+const versionLoading = ref(false);
+const versionError = ref("");
+const commitCopied = ref(false);
+
+async function loadVersionPanel() {
+  if (versionLoading.value) return;
+  versionLoading.value = true;
+  versionError.value = "";
+  try {
+    versionInfo.value = await fetchVersion();
+  } catch (e) {
+    versionInfo.value = null;
+    versionError.value = apiErrorMessage(e, "Could not reach the instance to ask what it is running.");
+  } finally {
+    versionLoading.value = false;
+  }
+}
+
+async function copyCommit() {
+  if (!versionInfo.value?.commit) return;
+  await copyToClipboard(versionInfo.value.commit);
+  commitCopied.value = true;
+  setTimeout(() => { commitCopied.value = false; }, 2000);
+}
 const restoreFileInput = ref<HTMLInputElement | null>(null);
 
 // Migrate stored "admin" → "config"; unknown tabs fall back to "general"
@@ -201,6 +252,7 @@ function _loadTabContent(tab: string) {
     else if (tab === "logs") loadLogsPanel();
     else if (tab === "groups") loadGroupsPanel();
     else if (tab === "areas") canonStore.fetchCatalog(true);
+    else if (tab === "config" && !versionInfo.value) loadVersionPanel();
   }
   if (tab === "apikeys") { fetchApiKeys(); }
 }
@@ -554,10 +606,6 @@ function toggleProfileWorkDay(day: string) {
 function emptyTagsFetch(): Promise<string[]> { return Promise.resolve([]) }
 
 onMounted(async () => {
-  try {
-    const v = await apiGet<{ version: string }>('/api/version')
-    appVersion.value = v.version
-  } catch { /* non-critical */ }
   await store.fetchSettings();
   newEmail.value = authStore.user?.email ?? "";
 
@@ -573,6 +621,9 @@ onMounted(async () => {
     kbInjectTopK.value = allSettings.kb_autoinject_top_k;
   }
   kbWritePathEnabled.value = allSettings.kb_writepath_enabled !== "false";
+  if (allSettings.kb_rulehint_threshold !== undefined) {
+    kbRuleHintThreshold.value = allSettings.kb_rulehint_threshold;
+  }
   if (allSettings.kb_writepath_threshold !== undefined) {
     kbWritePathThreshold.value = allSettings.kb_writepath_threshold;
   }
@@ -727,7 +778,7 @@ async function exportData(scope: "user" | "full") {
   exporting.value = true;
   try {
     const url = scope === "full" ? "/api/admin/backup" : "/api/admin/backup?scope=user";
-    const res = await fetch(url);
+    const res = await fetch(url, { signal: bulkDeadline() });
     if (!res.ok) {
       const body = await res.json().catch(() => ({ error: `Error ${res.status}` }));
       throw new Error((body as Record<string, string>).error || `Error ${res.status}`);
@@ -752,7 +803,7 @@ const exportingNotes = ref(false);
 async function exportNotes(format: "markdown" | "json") {
   exportingNotes.value = true;
   try {
-    const res = await fetch(`/api/export?format=${format}`);
+    const res = await fetch(`/api/export?format=${format}`, { signal: bulkDeadline() });
     if (!res.ok) throw new Error(`Error ${res.status}`);
     const blob = await res.blob();
     const ext = format === "json" ? "json" : "zip";
@@ -981,6 +1032,7 @@ async function handleRestoreFile(event: Event) {
       method: "POST",
       headers: { "Content-Type": "application/json" },
       body: JSON.stringify(data),
+      signal: bulkDeadline(),
     });
     if (!res.ok) {
       const body = await res.json().catch(() => ({ error: `Error ${res.status}` }));
@@ -1417,6 +1469,29 @@ async function deleteUser(userId: number) {
             location, not by resemblance.
           </p>
         </div>
+        <div class="field">
+          <label for="kb-rulehint-threshold">Standing-rule confidence threshold (0–1)</label>
+          <input
+            id="kb-rulehint-threshold"
+            v-model="kbRuleHintThreshold"
+            type="number"
+            min="0"
+            max="1"
+            step="0.01"
+            class="fs-input input"
+            style="max-width: 8rem"
+          />
+          <p class="field-hint">
+            The same hint can mention a standing rule whose trigger resembles what's
+            being written — only rules marked <em>conditional</em>, since always-on
+            ones are already loaded. Stricter again than the threshold above, because
+            there are far fewer rules than snippets: with a small set, something
+            always ranks first, so the bar has to carry more of the judgement.
+            Raise it if rules keep arriving unread; lower it if a rule you needed
+            never showed up. Settings → check the pull-through in
+            <code>retrieval_telemetry</code> to see which is happening.
+          </p>
+        </div>
         <!-- A design system belongs to a PROJECT, and the picker for it lives on
              the project. There was a setting here that designated the system
              this install's own interface was built from; it only ever described
@@ -2109,6 +2184,48 @@ async function deleteUser(userId: number) {
     <!-- ── Admin ── -->
     <div v-if="authStore.isAdmin" v-show="activeTab === 'config'" class="settings-grid">
 
+      <section class="settings-section full-width">
+        <h2>What's running</h2>
+        <p class="section-desc">
+          The build serving this page. Paste the commit into a <code>:sha</code> image
+          lookup to check the registry and the app agree about what was published.
+        </p>
+
+        <div v-if="versionLoading" class="state-msg">Reading the ledger&hellip;</div>
+        <div v-else-if="versionError" class="error-msg">
+          {{ versionError }}
+          <button class="btn-ghost btn-compact version-retry" @click="loadVersionPanel">Try again</button>
+        </div>
+        <dl v-else-if="versionInfo" class="version-grid">
+          <dt>Version</dt>
+          <dd class="version-value">{{ versionInfo.version }}</dd>
+
+          <dt>Channel</dt>
+          <dd :class="versionInfo.channel === undefined ? 'version-unknown' : 'version-value'">
+            {{ versionInfo.channel ?? "unknown" }}
+          </dd>
+
+          <dt>Commit</dt>
+          <dd v-if="versionInfo.commit" class="version-value version-commit">
+            <span class="version-sha">{{ versionInfo.commit }}</span>
+            <button class="btn-ghost btn-compact" @click="copyCommit">
+              {{ commitCopied ? "Copied" : "Copy" }}
+            </button>
+          </dd>
+          <dd v-else class="version-unknown">unknown</dd>
+
+          <dt>Build</dt>
+          <!-- The ordering key, kept because its ABSENCE is the diagnostic one:
+               no key means this build is not part of any update order, which is
+               what a local or hand-built image looks like. `??` not `||` — 0 is
+               a legitimate key. -->
+          <dd :class="versionInfo.build === undefined ? 'version-unknown' : 'version-value'">
+            {{ versionInfo.build ?? "unknown" }}
+          </dd>
+        </dl>
+        <div v-else class="empty-msg">Nothing asked yet.</div>
+      </section>
+
       <section class="settings-section full-width">
         <h2>Application URL</h2>
         <p class="section-desc">
@@ -2768,6 +2885,45 @@ async function deleteUser(userId: number) {
   letter-spacing: 0.07em;
   color: var(--fs-text-tertiary);
 }
+/* What's running — a definition list of instance facts. Spacing/geometry only;
+   colour and type come from the tokens. */
+.version-grid {
+  display: grid;
+  grid-template-columns: max-content 1fr;
+  gap: 0.4rem 1rem;
+  margin: 0;
+  align-items: baseline;
+}
+.version-grid dt {
+  font-size: 0.8rem;
+  color: var(--fs-text-secondary);
+}
+.version-grid dd {
+  margin: 0;
+  font-size: 0.875rem;
+  font-family: var(--fs-font-mono);
+  color: var(--fs-text-primary);
+}
+/* An absent field reads as absent — never as a blank, and never styled to look
+   like a value it does not have (#3127 checklist 12). */
+.version-grid dd.version-unknown {
+  font-family: inherit;
+  font-style: italic;
+  color: var(--fs-text-tertiary);
+}
+.version-commit {
+  display: flex;
+  align-items: center;
+  gap: 0.5rem;
+  flex-wrap: wrap;
+}
+.version-sha {
+  overflow-wrap: anywhere;
+}
+.version-retry {
+  margin-left: 0.5rem;
+}
+
 .section-desc {
   margin: 0 0 1rem;
   font-size: 0.875rem;

frontend/src/views/SnippetListView.vue

@@ -9,6 +9,7 @@ import {
   type SnippetListItem,
 } from "@/api/snippets";
 import { useToastStore } from "@/stores/toast";
+import UsageBadge from "@/components/UsageBadge.vue";
 
 const router = useRouter();
 const toast = useToastStore();
@@ -198,23 +199,6 @@ function languageOf(tags: string[]): string {
   return tags.find((t) => t && t !== "snippet") ?? "";
 }
 
-/** A snippet that has been offered repeatedly and never opened. The threshold
- *  is 3 rather than 1 because one or two surfacings is noise — the record may
- *  simply not have come up in a relevant context yet. */
-function isDeadWeight(s: SnippetListItem): boolean {
-  const u = s.usage;
-  return !!u && u.pull_count === 0 && u.surfaced_count >= 3;
-}
-
-/** Short badge text, or "" to render nothing. A record nobody has surfaced yet
- *  gets no badge at all: "0 / 0" would read as a verdict when it's an absence
- *  of evidence. */
-function usageBadge(s: SnippetListItem): string {
-  const u = s.usage;
-  if (!u || u.surfaced_count === 0) return "";
-  return `${u.pull_count}/${u.surfaced_count} used`;
-}
-
 /** Short label for the drift verdict, or "" when there's nothing to say.
  *  An expired verdict is reported as "unchecked" whatever it used to say —
  *  it was about code that is no longer in the record. */
@@ -254,22 +238,13 @@ function driftTitle(s: SnippetListItem): string {
   return v.detail ? `${when}: ${what}. ${v.detail}` : `${when}: ${what}.`;
 }
 
-function usageTitle(s: SnippetListItem): string {
-  const u = s.usage;
-  if (!u) return "";
-  const last = u.last_pulled_at
-    ? `Last opened ${new Date(u.last_pulled_at).toLocaleDateString()}.`
-    : "Never opened.";
-  const verdict = isDeadWeight(s)
-    ? " Offered repeatedly without ever being opened — consider rewriting its" +
-      " “when to reach for it” so it says when, or deleting it. It takes a slot" +
-      " in every future auto-inject menu."
-    : "";
-  return (
-    `Surfaced to an agent ${u.surfaced_count}×, opened in full ` +
-    `${u.pull_count}×. ${last}${verdict}`
-  );
-}
+/** The dead-weight nudge for a SNIPPET, passed to the shared badge. Kept here
+ *  rather than inside the component because the remedy is kind-specific — a
+ *  rule in the same position gets different advice (milestone 333 step 5). */
+const SNIPPET_DEAD_WEIGHT =
+  "Offered repeatedly without ever being opened — consider rewriting its " +
+  "“when to reach for it” so it says when, or deleting it. It takes a slot " +
+  "in every future auto-inject menu.";
 </script>
 
 <template>
@@ -456,14 +431,7 @@ function usageTitle(s: SnippetListItem): string {
           <span v-if="driftBadge(s)" class="drift-tag" :title="driftTitle(s)">
             {{ driftBadge(s) }}
           </span>
-          <span
-            v-if="usageBadge(s)"
-            class="usage-tag"
-            :class="{ 'usage-dead': isDeadWeight(s) }"
-            :title="usageTitle(s)"
-          >
-            {{ usageBadge(s) }}
-          </span>
+          <UsageBadge :usage="s.usage" :dead-weight-advice="SNIPPET_DEAD_WEIGHT" />
           <span v-if="s.shared" class="shared-tag" :title="`Shared by ${s.owner ?? 'another user'} — a suggestion, not your own record`">
             by {{ s.owner ?? "another user" }}
           </span>
@@ -757,23 +725,6 @@ function usageTitle(s: SnippetListItem): string {
   color: var(--fs-error-fg);
 }
 
-.usage-tag {
-  font-size: 0.7rem;
-  padding: 0.1rem 0.4rem;
-  border-radius: 4px;
-  white-space: nowrap;
-  font-variant-numeric: tabular-nums;
-  background: color-mix(in srgb, var(--fs-text-tertiary) 15%, transparent);
-  color: var(--fs-text-tertiary-fg);
-}
-
-/* Dead weight is a nudge, not an error — it warns in the warning colour rather
-   than the danger one, because the record isn't broken, just unearned. */
-.usage-tag.usage-dead {
-  background: color-mix(in srgb, var(--fs-warning) 18%, transparent);
-  color: var(--fs-warning-fg);
-}
-
 /* Header + select-mode */
 .header-actions {
   display: flex;

plugin/.claude-plugin/plugin.json

@@ -1,7 +1,7 @@
 {
   "name": "scribe",
   "description": "Scribe system-of-record for Claude Code: MCP tools over your notes/tasks/projects/rules, a session-start push channel that surfaces your always-on rules + active-project context, process-skills (writing-plans, systematic-debugging, verification, brainstorming, reusing-code), and your saved Scribe Processes auto-surfaced as skills (/scribe:sync). Replaces superpowers + file-memory with one app-backed plugin.",
-  "version": "0.1.48",
+  "version": "2026.09.09.0408",
   "author": {
     "name": "Bryan Van Deusen"
   },

plugin/README.md

@@ -78,8 +78,13 @@ On install you'll be asked for:
 
 ## Notes
 
-- Set a `version` bump in `.claude-plugin/plugin.json` per release so clients
-  pick up changes.
+- **Do not hand-edit `version` in `.claude-plugin/plugin.json`.** It is minted
+  from the clock — run `python3 scripts/mint_plugin_version.py` (or `make
+  mint-plugin`, where `make` is installed) after changing anything under
+  `plugin/`, and commit the result. The installer decides whether to refresh the cache it
+  executes from by comparing that string, so content that ships without a new
+  version reaches the repo and stops there (#2209). CI fails the lane if you
+  forget.
 - The session-start, auto-inject and prior-art hooks need only a **read**-scoped
   key; the MCP tools need **write** scope to create/update. Every hook is a GET
   for that reason — a read key cannot POST.

plugin/hooks/hooks.json

@@ -33,6 +33,15 @@
             "command": "bash \"${CLAUDE_PLUGIN_ROOT}/hooks/scribe_prior_art.sh\""
           }
         ]
+      },
+      {
+        "matcher": "Bash",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "bash \"${CLAUDE_PLUGIN_ROOT}/hooks/scribe_tool_rules.sh\""
+          }
+        ]
       }
     ],
     "PostToolUse": [

plugin/hooks/scribe_session_context.sh

@@ -55,6 +55,53 @@ here=$(CDPATH= cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd) || exit 0
 event=$(cat 2>/dev/null || true)
 source=$(printf '%s' "$event" | jq -r '.source // empty' 2>/dev/null) || source=""
 
+# --- The rule ledger outlives the context it describes (#3749) ---
+#
+# scribe_prior_art.sh and scribe_tool_rules.sh record every rule id they have
+# named in <state>/<sid>.rules.ids and hand it back as exclude_rule_ids, so a
+# rule is named once per session and then goes quiet. That is right while the
+# session still HOLDS what it was told, and wrong the moment it does not.
+#
+# A compaction summarizes the earlier injections away and does not touch the
+# filesystem, so the rule ends up absent from context AND still excluded —
+# unreachable for the rest of the session. The banner below tells the model to
+# re-pull its ALWAYS-ON rules, but a rule an arm surfaced is conditional and is
+# not in that set, so it has no other way back. The rules most likely to be in
+# this state are the ones that fire most often, which is to say the ones that
+# apply most.
+#
+# The session id survives a compaction — the etag marker further down is
+# rewritten on `compact` and keyed by session_id, which is only meaningful if
+# the id is stable — so the stale ledger is genuinely found again, not orphaned.
+#
+# CLEARED ON THE SOURCES THAT DESTROY CONTEXT, AND ONLY THOSE:
+#
+#   compact  CLEAR — summarized away; the file survived.
+#   clear    CLEAR — context wiped.
+#   startup  nothing to do: a new session id means a new, empty file.
+#   resume   KEEP. The context was genuinely restored, so the ledger still
+#            describes what the session holds. Clearing here would re-surface
+#            every rule after a restore that lost nothing — the mirror error.
+#   fork     KEEP, and the answer is the same whichever way forks are keyed: a
+#            fork carries the conversation, so if it inherits the id the ledger
+#            is accurate, and if it gets a new one the file is empty anyway.
+#
+# ONLY the rules ledger. The same directory holds .ids / .sync.ids /
+# .derive.ids for the note arms. Whether a surfaced NOTE should return after a
+# compaction is a different question with a different answer, and leaving those
+# alone is a decision rather than an oversight.
+case "$source" in
+  compact|clear)
+    sid=$(printf '%s' "$event" | jq -r '.session_id // empty' 2>/dev/null) || sid=""
+    if [ -n "$sid" ]; then
+      safe_sid=$(printf '%s' "$sid" | tr -c 'A-Za-z0-9._-' '_')
+      # Best-effort, like every other filesystem touch in these hooks: a ledger
+      # that cannot be removed costs a repeated exclusion, never a session.
+      rm -f "${TMPDIR:-/tmp}/scribe-priorart/${safe_sid}.rules.ids" 2>/dev/null || true
+    fi
+    ;;
+esac
+
 out=""
 # Append $1 to $out, separated by a horizontal rule when $out already has content.
 append() { if [ -n "$out" ]; then out="${out}"$'\n\n---\n\n'"$1"; else out="$1"; fi; }

plugin/hooks/scribe_static_context.md

@@ -21,6 +21,16 @@ for the operator's work, and as your own working memory across sessions.
   compaction — call `list_always_on_rules()` (and `enter_project()` when a
   project is in scope) BEFORE acting. When a loaded rule and a default habit
   disagree, the rule wins; if no rule speaks to it, ask rather than assume.
+- **What you loaded is not all of the rules.** Only the always-on tier arrives
+  that way; conditional rules are RETRIEVED, and one you were never handed
+  binds exactly as hard. So before a consequential act, `search` for a rule
+  about it (`content_type="rule"`) rather than concluding from an empty
+  loaded set that nothing applies. "I was not told" is not the same as "there
+  is no rule," and only one of those is checkable.
+  This bites hardest on which TOOL to reach for — curling an API that has an
+  MCP client, standing up a local stack, running a suite CI owns. Those feel
+  like mechanics rather than decisions, so they raise no doubt and generate no
+  query; the moment you are most confident is the moment to look.
 - **Recall before acting** — before you answer anything about the operator's
   work or start a task, `search` Scribe first; assume a related note, task, or
   decision already exists. Concretely, reach for recall whenever a request

plugin/hooks/scribe_tool_rules.sh

@@ -0,0 +1,116 @@
+#!/usr/bin/env bash
+# Scribe — PreToolUse rule arm for ACTIONS (#3476).
+#
+# The sibling of scribe_prior_art.sh. That hook is registered on Write|Edit and
+# asks "what is recorded about the file being written". This one asks "does a
+# standing rule speak to the command about to be run" — the question nothing
+# could ask before, and the reason every rule about which tool to reach for had
+# to live in the always-on preload instead.
+#
+# WHY A HOOK AND NOT AN INSTRUCTION. A reflex generates no query (note #3089):
+# you reach for `curl` confidently, with no moment of doubt, so a surface that
+# waits to be asked never fires. Here nothing is asked — the tool call IS the
+# query, and the reflex has to become a tool call before it can do anything.
+#
+# SILENT ON OUTAGE, deliberately, unlike the prior-art hook. A write is
+# occasional; a Bash call is not, and an "instance did not answer" line before
+# every command is the noise that gets a channel muted. scribe_prior_art.sh
+# still speaks for both when the instance is down.
+#
+# Env:
+#   SCRIBE_URL / SCRIBE_TOKEN override for the settings.json dogfooding path.
+
+command -v jq   >/dev/null 2>&1 || exit 0
+command -v curl >/dev/null 2>&1 || exit 0
+
+# PreToolUse delivers { session_id, cwd, tool_name, tool_input: {...}, ... }
+event=$(cat 2>/dev/null || true)
+tool_name=$(printf '%s' "$event" | jq -r '.tool_name // empty' 2>/dev/null) || exit 0
+session_id=$(printf '%s' "$event" | jq -r '.session_id // empty' 2>/dev/null) || session_id=""
+event_cwd=$(printf '%s' "$event" | jq -r '.cwd // empty' 2>/dev/null) || event_cwd=""
+
+[ -n "$tool_name" ] || exit 0
+
+# The action, as text. `.command` is Bash's field; the fallbacks let the matcher
+# in hooks.json widen to other tools without this script changing — which is the
+# whole reason the server side takes a name and a string rather than a schema.
+command_text=$(printf '%s' "$event" | jq -r '
+  .tool_input.command //
+  .tool_input.url //
+  .tool_input.prompt //
+  empty' 2>/dev/null) || command_text=""
+
+[ -n "$command_text" ] || exit 0
+
+# shellcheck source=plugin/hooks/scribe_defs.sh
+. "$(dirname "${BASH_SOURCE[0]}")/scribe_defs.sh"
+
+# scribe_config, not a hand-rolled pair of parameter expansions: it also treats
+# an UNEXPANDED `${...}` placeholder as unset, which would otherwise be sent as
+# a garbage Bearer token and 401 on every call (#2198's class).
+scribe_config || exit 0
+
+# Bounded before encoding: a heredoc or a pasted script can be enormous, and
+# the verb and its target — the part a rule is about — sit at the front. The
+# server bounds it again; this keeps a huge payload off the wire in the first
+# place. `head -c`, never `cut -c`: cut truncates each LINE and caps nothing.
+command_text=$(printf '%s' "$command_text" | head -c 2000)
+
+# -sRr, never -rR: jq -R without -s reads LINE BY LINE, so a multi-line command
+# would encode per line and join with raw newlines — an invalid URL.
+cmd_enc=$(printf '%s' "$command_text" | jq -sRr '@uri' 2>/dev/null) || exit 0
+tool_enc=$(printf '%s' "$tool_name" | jq -sRr '@uri' 2>/dev/null) || exit 0
+
+repo_q=""
+lookup_dir=${event_cwd:-${CLAUDE_PROJECT_DIR:-$PWD}}
+repo_remote=$(git -C "$lookup_dir" remote get-url origin 2>/dev/null || true)
+if [ -n "$repo_remote" ]; then
+  repo_enc=$(printf '%s' "$repo_remote" | jq -sRr '@uri' 2>/dev/null) || repo_enc=""
+  [ -n "$repo_enc" ] && repo_q="&repo=${repo_enc}"
+fi
+
+# THE SHARED SESSION LEDGER, and the thing most worth getting right here.
+#
+# scribe_prior_art.sh keeps the rules it has already named in
+# <state>/<sid>.rules.ids and passes them as exclude_rule_ids. This hook reads
+# and appends to that SAME file rather than keeping its own: two ledgers would
+# mean a rule named by one arm gets re-offered by the other, and the hint that
+# fires most often is exactly the one that must not repeat itself.
+#
+# The directory keeps the prior-art name on purpose — renaming it would orphan
+# every live session's state for a cosmetic gain.
+state_dir="${TMPDIR:-/tmp}/scribe-priorart"
+mkdir -p "$state_dir" 2>/dev/null || true
+rulefile=""
+rule_exclude_q=""
+if [ -n "$session_id" ]; then
+  safe_sid=$(printf '%s' "$session_id" | tr -c 'A-Za-z0-9._-' '_')
+  rulefile="$state_dir/${safe_sid}.rules.ids"
+  if [ -f "$rulefile" ]; then
+    rule_seen=$(tr '\n' ',' < "$rulefile" 2>/dev/null | sed 's/,$//')
+    [ -n "$rule_seen" ] && rule_exclude_q="&exclude_rule_ids=${rule_seen}"
+  fi
+fi
+
+# `|| exit 0` here, unlike the prior-art hook: there is no local arm whose
+# finding would be discarded, and an outage line before every command is worse
+# than silence. See the header.
+body=$(curl -fsS --max-time 5 \
+  -H "Authorization: Bearer ${token}" \
+  "${url%/}/api/plugin/tool-rules?tool=${tool_enc}&command=${cmd_enc}${repo_q}${rule_exclude_q}" 2>/dev/null) || exit 0
+
+context=$(printf '%s' "$body" | jq -r '.context // empty' 2>/dev/null) || exit 0
+[ -n "$context" ] || exit 0
+
+# Remember what was named so it is not repeated this session.
+if [ -n "$rulefile" ]; then
+  printf '%s' "$body" | jq -r '(.rule_ids // [])[]?' 2>/dev/null >> "$rulefile" || true
+fi
+
+jq -cn --arg ctx "$context" '{
+  hookSpecificOutput: {
+    hookEventName: "PreToolUse",
+    additionalContext: $ctx
+  }
+}' 2>/dev/null || true
+exit 0

plugin/skills/using-scribe/SKILL.md

@@ -56,10 +56,31 @@ Two constraints on *how* that's achieved:
    re-deriving it or opening a duplicate. When a project is in scope, pass its
    `project_id` so results stay scoped.
 
-2. **Standing rules are binding.** Load them via `list_always_on_rules()` at
-   session start (see "Do this first"); treat every one as binding. Pull a
-   rule's full statement with `get_rule(id)` when it's about to bite. When a
-   project is in scope, `enter_project(id)` also returns its applicable rules.
+2. **Standing rules are binding — and the ones you were handed are not all of
+   them.** Load the resident set via `list_always_on_rules()` at session start
+   (see "Do this first"); treat every one as binding. Pull a rule's full
+   statement with `get_rule(id)` when it's about to bite. When a project is in
+   scope, `enter_project(id)` also returns its applicable rules.
+
+   Rules come in two tiers. **Always-on** rules are delivered — they arrive
+   whether or not you ask. **Conditional** rules are RETRIEVED, and one binds
+   just as hard for never having been handed to you. So before a consequential
+   act, `search(content_type="rule")` on what you are about to do. An empty
+   loaded set is not evidence that no rule applies; it is only evidence that
+   none was pushed, and those are different claims.
+
+   The tier split exists because delivery does not scale: every resident rule
+   costs tokens in every session forever, so a rulebook that grows past a few
+   dozen either stops growing or stops fitting. Retrieval is what lets the
+   rulebook keep growing — but retrieval only fires if something asks.
+
+   **Ask hardest where you feel most certain.** Rules about which TOOL to reach
+   for — use the forge's MCP client rather than curling its API, don't stand up
+   a local stack, don't run the suite CI owns — govern moves that feel like
+   mechanics rather than decisions. A reflex raises no doubt, so it generates
+   no query, so the rule that would have stopped it is never retrieved. That is
+   the failure this instruction exists to prevent, and confidence is its only
+   warning sign.
 
 3. **Update over duplicate.** When recording, prefer updating an existing
    note/rule/task over creating a new one. Search first; revise what's there.

scripts/bump_fable_mcp_version.sh

@@ -1,17 +0,0 @@
-#!/usr/bin/env bash
-# Bump the patch segment of fable-mcp/pyproject.toml version and stage the file.
-# Usage: called automatically by the Claude Code pre-commit hook, or manually.
-set -euo pipefail
-
-REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
-FILE="$REPO_ROOT/fable-mcp/pyproject.toml"
-
-current=$(grep '^version = ' "$FILE" | sed 's/version = "\(.*\)"/\1/')
-major=$(echo "$current" | cut -d. -f1)
-minor=$(echo "$current" | cut -d. -f2)
-patch=$(echo "$current" | cut -d. -f3)
-new_version="$major.$minor.$((patch + 1))"
-
-sed -i "s/^version = \"$current\"/version = \"$new_version\"/" "$FILE"
-git -C "$REPO_ROOT" add "$FILE"
-echo "fable-mcp: $current → $new_version"

scripts/check_plugin.py

@@ -13,9 +13,20 @@ separate defects have reached a live install through that path:
     install, because `plugin.json`'s version wasn't bumped and the installer
     compares versions to decide whether to refresh its cache.
 
-The rule for the second one was already written down and was still missed. A
-written rule that depends on being remembered during a long session is not a
-control; this is.
+Both were fixed. The second was fixed TWICE — once by bumping the number, and
+then properly, by removing the class it came from: `plugin.json`'s version is
+no longer a value anybody chooses. `scripts/mint_plugin_version.py` derives it
+from the clock (`make mint-plugin`), and `check_version_is_minted` below fails
+the lane when shipped content moved and the version did not.
+
+State exactly what that did and did not remove, because a rationale that
+overstates its own control is how the control gets trusted past its limit, and
+because the paragraph this replaces was itself read that way. Gone: having to
+remember which NUMBER to write, and the whole question of whether a chosen
+number was the right one. Not gone: the mint still has to be RUN, and
+forgetting to run it is still possible. What changed is that forgetting is now
+LOUD — a red lane on the batch that forgot, instead of a silent no-op found
+weeks later when somebody says "I don't think it updated" (#2220).
 
 shellcheck and jq are NOT in `ci-python` (verified against CI-runner's Dockerfile
 and scripts/install-common.sh, not from memory — rule #37). CI installs both
@@ -31,8 +42,15 @@ itself loudly, because a check that quietly no-ops is the failure mode this
 whole file exists to prevent.
 
 Usage:
-    python3 scripts/check_plugin.py            # all checks
-    python3 scripts/check_plugin.py --no-version   # skip the bump check
+    python3 scripts/check_plugin.py                # all checks
+    python3 scripts/check_plugin.py --no-version   # on `main` only — see below
+
+`--no-version` exists for ONE case. The version is measured against
+`origin/main`, so on `main` itself the comparison is against itself and answers
+nothing; the syntax, pattern and marker checks are the only ones that mean
+anything there. It is NOT a way past a red lane — see
+`check_version_is_minted`, whose whole design is shaped by keeping this flag
+out of anyone's muscle memory.
 """
 from __future__ import annotations
 
@@ -43,16 +61,90 @@ import re
 import shutil
 import subprocess
 import sys
+from datetime import datetime, timedelta, timezone
 from pathlib import Path
 
 ROOT = Path(__file__).resolve().parents[1]
+
+# The shape contract is ONE definition, shared with the script that mints it —
+# a checker carrying its own copy of the format would drift from the minter
+# and pass values the minter can no longer produce. Explicit path insert
+# because this file runs both as `python3 scripts/check_plugin.py` (which puts
+# `scripts/` on the path, not the root) and as an import from the test suite.
+sys.path.insert(0, str(ROOT))
+from scripts.mint_plugin_version import VERSION_RE  # noqa: E402
+
 PLUGIN_DIR = ROOT / "plugin"
 HOOKS_DIR = PLUGIN_DIR / "hooks"
 MANIFEST = PLUGIN_DIR / ".claude-plugin" / "plugin.json"
 
-# Paths whose contents reach an install. Keep in step with the workflow's
-# `paths:` filter — a path that ships but isn't checked here is the gap again.
-SHIPPED = ("plugin", ".claude-plugin")
+# ── What ships, and what decides what it says about itself ─────────────────
+#
+# ONE definition (#3127 §3, milestone 334 step 2). It has TWO consumers that
+# need different granularities, and conflating them is the bug:
+#
+#   the workflow's `paths:` trigger   whole paths   should CI run at all?
+#   the version check                 paths MINUS   should the version
+#                                     the manifest  have moved?
+#                                     `version`
+#
+# The second one is why this is not just a tuple of paths. `plugin.json` lives
+# INSIDE `plugin/`, so a version bump is itself a change to the shipped set —
+# and a check that reads the set naively then treats the bump as its own
+# justification. Any bump passes, no bump fails, and it has proved nothing.
+# `shipped_content_changed` below is the exclusion-aware reader.
+#
+# The exclusion is that ONE FIELD, never the whole file: `plugin.json` also
+# carries description, mcpServers and userConfig, all of which reach an
+# install and all of which matter. Excluding the file wholesale would mean a
+# userConfig-only edit computes an unchanged version and never refreshes —
+# #2209 again with a narrower trigger.
+SHIPPED_PATHS = ("plugin", ".claude-plugin")
+
+# Files that decide what a published artifact SAYS ABOUT ITSELF — kept as a
+# table so the next artifact is a one-line addition rather than a third
+# bespoke guard (#3127 §3). The membership test is NOT "is this copied into
+# the artifact?" but "can changing this file change the published bytes, or
+# what the artifact says about itself?" — FC learned that twice in four days
+# (#3156, #3202), and a deriver is never in the COPY list.
+#
+# Note what is absent: a CHECKER does not belong here. Whatever validates a
+# version decides whether the lane goes red, not what any artifact reports,
+# so `check_plugin.py` itself is not a deriver, while the script that mints
+# the plugin version is.
+DERIVERS: dict[str, tuple[str, ...]] = {
+    # The "Generate image tags and version" step computes the server image's
+    # name, ordering key and channel (#3298).
+    ".forgejo/workflows/ci.yml": ("server-image",),
+    # Decides the plugin's version FORMAT, so it decides what every future
+    # manifest says about itself (milestone 334 step 3).
+    "scripts/mint_plugin_version.py": ("plugin",),
+}
+
+
+def version_relevant_paths() -> tuple[str, ...]:
+    """Everything a change to which must produce a NEW plugin version.
+
+    Wider than `SHIPPED_PATHS`, and #3127 §3's asymmetry is why it has to be:
+
+        A change to how the VERSION is computed is compared against nothing at
+        all. Left out, the published artifact goes on reporting the OLD value
+        indefinitely.
+
+    Concretely — change the mint script's format string, change nothing else,
+    and a diff over the shipped paths alone reports "no content change, the
+    version need not move". The manifest then keeps a value in the old format
+    forever and nothing ever says so. The mint script reaches no install and
+    belongs here anyway; that is #3156's exact shape.
+
+    A CHECKER is deliberately not here. Whatever validates the version decides
+    whether the lane goes red, not what any artifact reports — so this file is
+    absent from its own set, and that is not an oversight.
+    """
+    return SHIPPED_PATHS + tuple(
+        path for path, artifacts in DERIVERS.items() if "plugin" in artifacts
+    )
+
 
 failures: list[str] = []
 
@@ -143,8 +235,6 @@ def check_patterns() -> None:
             ok(f"{rel}: no known-bad patterns")
 
 
-# --- the version bump ------------------------------------------------------
-
 # --- shellcheck ------------------------------------------------------------
 
 def check_shellcheck() -> None:
@@ -215,6 +305,16 @@ SMOKE_EVENTS: dict[str, str] = {
          "tool_input": {"file_path": "src/x.py",
                         "new_string": f"def {_ABSENT_SYM}():\n    pass\n"}}
     ),
+    # The pre-tool rule arm (#3476). A real Bash call, and one whose whole
+    # point is that it looks harmless: reaching for curl against the forge API
+    # is the reflex the arm exists to catch. With no instance it must stay
+    # SILENT — it is deliberately not an OUTAGE_SPEAKER, because a Bash call is
+    # not occasional and an outage line before every command gets the channel
+    # muted.
+    "scribe_tool_rules.sh": json.dumps(
+        {"session_id": "smoke", "cwd": ".", "tool_name": "Bash",
+         "tool_input": {"command": "curl -s https://example.invalid/api/v1/runs"}}
+    ),
     "scribe_sync_processes.sh": json.dumps({"source": "startup"}),
     "scribe_session_context.sh": json.dumps({"source": "startup"}),
     # The after-write hook (#2901) diffs the working tree; on CI's clean
@@ -391,80 +491,213 @@ def _git(*args: str) -> tuple[int, str]:
     return proc.returncode, (proc.stdout or proc.stderr).strip()
 
 
-def manifest_version(ref: str | None = None) -> str | None:
-    """The manifest version at `ref`, or in the working tree when ref is None."""
+def manifest_text(ref: str | None = None) -> str | None:
+    """The manifest's RAW TEXT at `ref`, or in the working tree when ref is None.
+
+    Split out from `manifest_version` because the exclusion below needs every
+    field except one, not the one field.
+    """
     if ref is None:
         try:
-            return json.loads(MANIFEST.read_text()).get("version")
-        except Exception:
+            return MANIFEST.read_text()
+        except OSError:
             return None
     rel = MANIFEST.relative_to(ROOT).as_posix()
     code, out = _git("show", f"{ref}:{rel}")
-    if code != 0:
+    return out if code == 0 else None
+
+
+def manifest_version(ref: str | None = None) -> str | None:
+    """The manifest version at `ref`, or in the working tree when ref is None."""
+    text = manifest_text(ref)
+    if text is None:
         return None
     try:
-        return json.loads(out).get("version")
+        return json.loads(text).get("version")
     except Exception:
         return None
 
 
-def check_version_bump(base: str = "origin/main") -> None:
-    """If shipped plugin content differs from `base`, the version must too.
+# Distinct from None, which is a legitimate "this manifest does not exist".
+_UNREADABLE = object()
 
-    Stated against the BASE BRANCH rather than the last commit on purpose. A
-    per-commit rule would demand a bump from every commit in a batch; what
-    actually matters is that whatever reaches an install carries a version the
-    installer can tell apart from the one already cached. One bump per batch,
-    which is also how a human would do it.
+
+def manifest_differs_beyond_version(a: str | None, b: str | None) -> bool:
+    """Do two `plugin.json` texts differ in anything OTHER than `version`?
+
+    THE exclusion, and it is kept pure — no git, no filesystem — because this
+    is the half worth testing hard and it needs no repository to exercise.
+
+    Compares PARSED objects rather than text, so reformatting, key reordering
+    and whitespace do not read as content changes. `version` is dropped from
+    both sides; everything else counts, which is what keeps a userConfig-only
+    or mcpServers-only edit demanding a new version.
+
+    Unreadable input answers True. The conservative direction is "demand a new
+    version": a spurious bump costs one cache refresh, while a missed one is
+    #2209 — the fix reaches the repo and stops there.
+    """
+    def without_version(text: str | None):
+        if text is None:
+            return None
+        try:
+            data = json.loads(text)
+        except Exception:
+            return _UNREADABLE
+        if not isinstance(data, dict):
+            return _UNREADABLE
+        return {k: v for k, v in data.items() if k != "version"}
+
+    left, right = without_version(a), without_version(b)
+    if left is _UNREADABLE or right is _UNREADABLE:
+        return True
+    return left != right
+
+
+def shipped_content_changed(base: str) -> tuple[bool | None, list[str]]:
+    """Has anything that REACHES AN INSTALL changed against `base`?
+
+    Returns `(changed, paths)`. `changed` is **None** when the question could
+    not be answered — a caller must never read that as "no", which is the
+    distinction #2663 cost weeks of zeroed telemetry to learn.
+
+    The manifest is special-cased, not excluded: if it is the ONLY thing that
+    moved and the only difference is `version`, nothing that reaches an
+    install has changed. Any other manifest field, or any other file, counts.
+
+    Reads `version_relevant_paths`, which is the shipped set PLUS the files
+    that decide the version — see there for why the deriver has to be in it.
+    """
+    code, out = _git("diff", "--name-only", base, "--", *version_relevant_paths())
+    if code != 0:
+        return None, []
+    paths = [p for p in out.splitlines() if p.strip()]
+    if not paths:
+        return False, []
+
+    rel_manifest = MANIFEST.relative_to(ROOT).as_posix()
+    if paths == [rel_manifest]:
+        return manifest_differs_beyond_version(
+            manifest_text(), manifest_text(base)
+        ), paths
+    return True, paths
+
+
+def check_version_is_minted(base: str = "origin/main") -> None:
+    """THE control (#3127 checklist 4), replacing "somebody remembers".
+
+    The checklist asks, of any hand-set component: *say what happens the
+    release somebody forgets it.* This is the answer — the lane goes red,
+    deterministically, because CI can compute whether the value should have
+    moved. Its predecessor could only ask "did the number move at all", which
+    any bump satisfied and which therefore proved nothing.
+
+    Four verdicts:
+
+      content changed, version did not   FAIL — this is #2209, exactly
+      version not in canonical shape     FAIL — see below
+      version implausibly in the future  FAIL — a bad clock or a hand-edit
+      version moved, content did not     pass, and say so
+
+    THE LAST ROW IS NOT A FAILURE, DELIBERATELY. A needless re-mint costs one
+    cache refresh and nothing else. Failing the lane over a harmless act is how
+    a check earns a `--no-version` in somebody's muscle memory and stops
+    running at all — which is the failure mode this whole file exists to
+    prevent. The implication that matters is one-directional: content changed
+    IMPLIES version moved.
+
+    A malformed version is worth failing on even though the installer would
+    accept it. `K4` returns the manifest string verbatim, and `H == "unknown"`
+    sets `forceOverwrite`, so a broken value either sorts as a normal string
+    or reinstalls the plugin every single session (#3325). Neither is loud.
+
+    Stated against the BASE BRANCH rather than the last commit, as its
+    predecessor was: a per-commit rule would demand a fresh mint from every
+    commit in a batch, when what matters is that whatever reaches an install
+    differs from what is cached. One mint per batch, which is also how a person
+    would do it.
     """
     code, _ = _git("rev-parse", "--verify", base)
     if code != 0:
         # Do NOT pass silently — a check that quietly no-ops is how this class
         # of bug survives in the first place.
         fail(
-            f"cannot resolve {base}, so the version-bump check could not run. "
+            f"cannot resolve {base}, so the minted-version check could not run. "
             f"Fetch it first — `git fetch --depth=1 origin main:refs/remotes/"
             f"origin/main` is enough, since this diffs two trees and needs no "
             f"common ancestor — or pass --no-version deliberately."
         )
         return
 
-    code, changed = _git("diff", "--name-only", base, "--", *SHIPPED)
-    if code != 0:
-        fail(f"git diff against {base} failed: {changed}")
-        return
-    if not changed.strip():
-        ok(f"no shipped plugin changes against {base} — version bump not required")
-        return
-
-    here, there = manifest_version(), manifest_version(base)
+    here = manifest_version()
     if here is None:
         fail(f"could not read a version from {MANIFEST.relative_to(ROOT)}")
         return
+    if not VERSION_RE.match(here):
+        fail(
+            f"the manifest version is {here!r}, which is not YYYY.MM.DD.HHMM.\n"
+            f"        One shape for every version in the family (#3127 checklist "
+            f"10), zero-padded so the midnight case renders 2026.01.05.0000.\n"
+            f"        Run `make mint-plugin`."
+        )
+        return
+
+    minted = datetime.strptime(here, "%Y.%m.%d.%H%M").replace(tzinfo=timezone.utc)
+    # A day of slack: the mint happens on a workstation and the lane runs
+    # later, so a *small* skew is ordinary. A value further out than that is
+    # a wrong clock or a typed year, and it makes the version lie about when
+    # it was minted.
+    if minted > datetime.now(timezone.utc) + timedelta(days=1):
+        fail(
+            f"the manifest version {here} is in the future. Either the clock "
+            f"that minted it is wrong, or it was typed by hand."
+        )
+        return
+
+    changed, paths = shipped_content_changed(base)
+    if changed is None:
+        fail(f"git diff against {base} failed, so the version check could not run")
+        return
+
+    there = manifest_version(base)
     if there is None:
         ok(f"no manifest on {base} — treating as a new plugin (version {here})")
         return
-    if here == there:
-        files = "\n          ".join(changed.splitlines())
+
+    if changed and here == there:
+        files = "\n          ".join(paths)
         fail(
-            f"plugin content changed but the manifest version is still {here}.\n"
-            f"        The installer compares versions to decide whether to refresh "
-            f"its cache, so an unchanged version means these edits reach the repo "
-            f"and stop there — the marketplace clone updates, the cache that "
-            f"actually executes does not (issue #2209).\n"
-            f"        Bump `version` in {MANIFEST.relative_to(ROOT)}.\n"
+            f"plugin content changed but the version is still {here}.\n"
+            f"        The installer decides whether to refresh its cache by "
+            f"comparing this string, so an unchanged version means these edits "
+            f"reach the repo and stop there — the marketplace clone updates, the "
+            f"cache that actually executes does not (#2209, #1040, #2220).\n"
+            f"        Run `make mint-plugin`.\n"
             f"        Changed:\n          {files}"
         )
+    elif changed:
+        ok(f"plugin content changed and the version was minted {there} -> {here}")
+    elif here != there:
+        # Not a failure — see the docstring. Named rather than silent, because
+        # the uninteresting cause (minted twice) and the interesting one (the
+        # version-relevant set is too narrow to see what actually changed)
+        # produce the same line, and only a person can tell them apart.
+        ok(
+            f"the version moved {there} -> {here} with no version-relevant "
+            f"change — harmless, unless something DID change that the set "
+            f"cannot see"
+        )
     else:
-        ok(f"plugin content changed and version moved {there} -> {here}")
+        ok(f"nothing version-relevant changed against {base} — no mint required")
 
 
 def main() -> int:
     parser = argparse.ArgumentParser(description=__doc__)
     parser.add_argument("--no-version", action="store_true",
-                        help="skip the manifest version-bump check")
+                        help="skip the minted-version check; for `main`, where "
+                             "it would be measured against itself")
     parser.add_argument("--base", default="origin/main",
-                        help="branch the version bump is measured against")
+                        help="branch the version is measured against")
     args = parser.parse_args()
 
     if not HOOKS_DIR.is_dir():
@@ -478,7 +711,7 @@ def main() -> int:
     check_local_prior_art_needs_no_instance()
     check_session_context_reports_its_version()
     if not args.no_version:
-        check_version_bump(args.base)
+        check_version_is_minted(args.base)
 
     print()
     if failures:

scripts/mint_plugin_version.py

@@ -0,0 +1,144 @@
+#!/usr/bin/env python3
+"""Mint the plugin's version — `YYYY.MM.DD.HHMM`, UTC, zero-padded.
+
+Run this whenever you change something under `plugin/` or `.claude-plugin/`,
+before you commit:
+
+    make mint-plugin        # or: python3 scripts/mint_plugin_version.py
+
+WHY A SCRIPT AND NOT A BUILD STEP. `plugin/` is not in the Docker image.
+Installs fetch it straight from this git repo via `.claude-plugin/
+marketplace.json`, so **a push IS the release** — there is no build between
+you committing and a user fetching, and therefore no moment at which CI could
+stamp a version in. Every other artifact in the family derives its version
+during a build (note #3127 §2). This one has no build to derive during.
+
+WHICH CLOCK, AND WHY IT DIFFERS FROM THE SERVER IMAGE — the divergence is
+deliberate, and it lives one directory away from its opposite, so it is
+exactly what a later "let's make these consistent" change would collapse:
+
+    server image   name from COMMIT time, ordering key from BUILD time
+                   (two lanes building one source must report one string;
+                   a rebuild of an older commit must not go backwards)
+    plugin         one value, from MINT time
+
+§2's reason for commit time is that two lanes build one source. The plugin has
+one lane and no build, so that reason does not reach it and paying its cost
+buys nothing. What is given up is reproducibility-from-history: you cannot
+recompute this value later, only verify that it moved when it had to.
+
+That trade is acceptable ONLY because of what #3325 established by reading the
+installer's code: the refresh test is `P.version === H`, plain string
+equality, with no ordering comparison anywhere. Where a comparator ORDERS, an
+unreproducible version is dangerous — nothing can check it is right. Where it
+only tests equality, "did it change when it should have" is the entire
+specification, and `check_plugin.py` checks that completely.
+
+The manifest is rewritten with a surgical replacement of the `version` line
+rather than `json.dump`, because its formatting and key order are not this
+script's to decide and a whole-file reformat would make every mint an
+unreadable diff.
+"""
+from __future__ import annotations
+
+import argparse
+import json
+import re
+import sys
+from datetime import datetime, timezone
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[1]
+MANIFEST = ROOT / "plugin" / ".claude-plugin" / "plugin.json"
+
+# Four dot-separated numeric fields, zero-padded, and nothing else — one shape
+# for every human-readable version in the family (#3127 checklist 10). The
+# padding is load-bearing for the midnight case the checklist names by hand:
+# 2026.01.05.0000, which an unpadded `%-H%M` would render as `0` and silently
+# shorten. Harmless while nothing orders these, wrong the moment anything does.
+VERSION_RE = re.compile(r"^\d{4}\.\d{2}\.\d{2}\.\d{4}$")
+VERSION_FORMAT = "%Y.%m.%d.%H%M"
+
+# The `version` line, captured so its surroundings survive byte-for-byte.
+VERSION_LINE_RE = re.compile(r'^(\s*"version"\s*:\s*")([^"]*)(".*)$', re.M)
+
+
+def mint(now: datetime | None = None) -> str:
+    """The version for this moment. UTC, always.
+
+    The conversion is not decoration: `strftime` renders whatever offset the
+    datetime carries, so without it two people minting the same instant in
+    different zones produce different strings — and the string IS the
+    artifact's identity. A naive datetime is read as UTC rather than as the
+    machine's zone, because that is this function's stated contract and
+    guessing the host's offset is how the bug comes back by another route.
+    """
+    moment = now or datetime.now(timezone.utc)
+    if moment.tzinfo is None:
+        moment = moment.replace(tzinfo=timezone.utc)
+    return moment.astimezone(timezone.utc).strftime(VERSION_FORMAT)
+
+
+def rewrite(text: str, version: str) -> str:
+    """`text` with its `version` value replaced, and everything else untouched.
+
+    Raises rather than falling back to a JSON round-trip: a manifest this
+    cannot match is one whose shape changed, and quietly reformatting the file
+    to cope would be a much larger edit than the caller asked for.
+    """
+    # Counted BEFORE substituting, not via subn's return: a capped `subn`
+    # reports the replacements it made, so a manifest with two `version` lines
+    # would look like a clean single match while the second one — the real one,
+    # perhaps — kept its old value.
+    matches = VERSION_LINE_RE.findall(text)
+    if len(matches) != 1:
+        raise ValueError(
+            f"expected exactly one `version` line in the manifest, found {len(matches)}"
+        )
+    return VERSION_LINE_RE.sub(
+        lambda m: f"{m.group(1)}{version}{m.group(3)}", text, count=1
+    )
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser(description="Mint the plugin's version.")
+    parser.add_argument(
+        "--check", action="store_true",
+        help="print the version that WOULD be minted and change nothing",
+    )
+    args = parser.parse_args()
+
+    version = mint()
+    if args.check:
+        print(version)
+        return 0
+
+    try:
+        text = MANIFEST.read_text()
+    except OSError as exc:
+        print(f"cannot read {MANIFEST.relative_to(ROOT)}: {exc}", file=sys.stderr)
+        return 1
+
+    try:
+        previous = json.loads(text).get("version")
+    except Exception:
+        previous = None
+
+    if previous == version:
+        # Same minute. Not an error — the value is already correct for now, and
+        # failing here would turn "I ran it twice" into a problem to solve.
+        print(f"plugin version already {version} (same minute) — unchanged")
+        return 0
+
+    try:
+        MANIFEST.write_text(rewrite(text, version))
+    except ValueError as exc:
+        print(f"{MANIFEST.relative_to(ROOT)}: {exc}", file=sys.stderr)
+        return 1
+
+    print(f"plugin version {previous} -> {version}")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())

scripts/pre_commit_fable_mcp.sh

@@ -1,39 +0,0 @@
-#!/usr/bin/env bash
-# Claude Code PreToolUse hook for Bash.
-# Reads the tool input JSON from stdin; if the command is a git commit
-# and fable-mcp files (other than pyproject.toml) are staged, bumps
-# the fable-mcp patch version before the commit proceeds.
-#
-# Exits 0 always so it never blocks the commit.
-
-set -euo pipefail
-
-REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
-
-input=$(cat)
-command=$(echo "$input" | python3 -c "
-import sys, json
-data = json.load(sys.stdin)
-# Claude Code sends {tool_input: {command: ...}}
-ti = data.get('tool_input', data)
-print(ti.get('command', ''))
-" 2>/dev/null || echo "")
-
-# Only act on git commit commands
-if ! echo "$command" | grep -qE "git commit"; then
-  exit 0
-fi
-
-cd "$REPO_ROOT"
-
-# Check if fable-mcp files other than pyproject.toml are staged
-fable_staged=$(git diff --cached --name-only 2>/dev/null \
-  | grep "^fable-mcp/" \
-  | grep -v "^fable-mcp/pyproject.toml$" \
-  || true)
-
-if [ -n "$fable_staged" ]; then
-  bash "$REPO_ROOT/scripts/bump_fable_mcp_version.sh"
-fi
-
-exit 0

src/scribe/mcp/server.py

@@ -45,6 +45,31 @@ from quart import Quart
 # The accepted cost: an agent that never opens create_note's docstring never
 # learns the field exists. Guidance lives in the create_note / update_note
 # docstrings and the using-scribe skill instead.
+#
+# Milestone 333 step 3 (2026-09-04) bought the HOW bullet's second clause —
+# search(content_type="rule") before a consequential act — by TRADING OUT
+# "Processes are saved procedures (follow verbatim)" and "Deletes are
+# trash-recoverable". Recorded so the trade is not silently reversed:
+#   - Both were already in test_instruction_surfaces_agree's DISPLACED_TOPICS
+#     and already stated on a delivered surface, so nothing fell off: the
+#     process reflex is in every scribe-proc-* skill listing (each says the
+#     process governs and is followed verbatim), and trash recovery is in the
+#     delete_*/list_trash/restore docstrings, which is where per-tool guidance
+#     belongs by this block's own doctrine.
+#   - What it bought is not per-tool guidance and has nowhere else to live at
+#     session-start altitude. Rules were retrievable only by RESIDENCY: the
+#     always-on preload put them in front of the agent, and nothing told a
+#     session to go looking for one it had not been handed. The tier split is
+#     therefore load-bearing on ANY install (rule 115): a delivered rule costs
+#     tokens in every session forever, so a rulebook that only delivers cannot
+#     grow past what one session can hold, and every rule worth keeping has to
+#     become resident to bind at all. Retrieval is what lets it keep growing —
+#     and retrieval fires only if something asks, which nothing told a session
+#     to do. A tool-choice reflex asks least of all (#3476, #161).
+#   - This states the PULL for conditional rules, exactly as the surrounding
+#     line states it for always-on ones. Rule 119 makes these surfaces the
+#     specification, so the same sentence lands on all three session-start
+#     surfaces, and test_instruction_surfaces_agree pins it.
 _INSTRUCTIONS = """
 Scribe is the operator's self-hosted second brain and system of record — and
 yours: recall from it before acting, record as you go. Keep no parallel copy
@@ -63,13 +88,13 @@ Hierarchy: Project -> Milestone -> Task/Note. The map, by purpose:
   active project_id to stay in scope.
 - WHERE work happens: Systems. Tag records with system_ids as you write;
   create_system when the area is unmodelled.
-- HOW: rules are binding — list_always_on_rules() at session start.
+- HOW: rules bind. list_always_on_rules() at start; before a consequential
+  act, search(content_type="rule") — the resident set is not all of them.
 - UI: the project's design system is binding — resolve_design_system /
   get_design_system_stylesheet before hand-writing a value.
 - REUSE: search snippets before writing a helper; record what you build with
   create_snippet; classify shapes against canon (classify_shapes) — a
-  consumer map is rows, never prose. Processes are saved procedures (follow
-  verbatim). Deletes are trash-recoverable.
+  consumer map is rows, never prose.
 
 A task is a note with status (*_note vs *_task tools).
 Creates are duplicate-gated: a near-match BLOCKS and returns the existing

src/scribe/mcp/tools/milestones.py

@@ -57,7 +57,7 @@ async def get_milestone(milestone_id: int) -> dict:
     return {
         "milestone": out,
         "steps": [t.to_dict() for t in steps],
-        **rulebooks_svc.rules_payload(applicable),
+        **rulebooks_svc.rules_payload(applicable, user_id=uid, source="get_milestone"),
     }
 
 

src/scribe/mcp/tools/projects.py

@@ -207,7 +207,7 @@ async def enter_project(project_id: int) -> dict:
         ],
         "design_system": design_system,
         "milestone_summary": milestone_summary,
-        **rulebooks_svc.rules_payload(applicable),
+        **rulebooks_svc.rules_payload(applicable, user_id=uid, source="enter_project"),
         "open_tasks": [
             {
                 "id": t.id, "title": t.title, "status": t.status,
@@ -251,7 +251,7 @@ async def get_project(project_id: int) -> dict:
     applicable = await rulebooks_svc.get_applicable_rules(
         project_id=project_id, user_id=uid,
     )
-    data.update(rulebooks_svc.rules_payload(applicable))
+    data.update(rulebooks_svc.rules_payload(applicable, user_id=uid, source="get_project"))
     return data
 
 

src/scribe/mcp/tools/rulebooks.py

@@ -18,6 +18,7 @@ from scribe.mcp._context import current_user_id
 from scribe.services import dedup as dedup_svc
 from scribe.services import rulebooks as rulebooks_svc
 from scribe.services import trash as trash_svc
+from scribe.services.rule_usage import record_rule_pulled, record_rule_surfaced
 
 
 # ── Rulebook CRUD ───────────────────────────────────────────────────────
@@ -264,6 +265,15 @@ async def list_always_on_rules(project_id: int = 0) -> dict:
     """
     uid = current_user_id()
     rules = await rulebooks_svc.list_always_on_rules(uid, project_id=project_id)
+    # AMBIENT source: the resident set, handed over whole. No ranker chose
+    # these, so they must not land in the pull-through numerator's denominator
+    # — but they must land SOMEWHERE, or the largest rule surface in the
+    # product stays the one surface its own scoreboard cannot see (#3473).
+    record_rule_surfaced(
+        user_id=uid,
+        rule_ids=[r.id for r in rules],
+        source="list_always_on_rules",
+    )
     return {
         "rules": [_rule_summary(r) for r in rules],
         "total": len(rules),
@@ -288,6 +298,11 @@ async def get_rule(rule_id: int) -> dict:
     rule = await rulebooks_svc.get_rule(rule_id, uid)
     if rule is None:
         raise ValueError(f"rule {rule_id} not found")
+    # THE pull that matters. The write-path rule arm's own message ends "Read
+    # it with get_rule(N)", so this is the exact action the hint asks for and
+    # the only evidence that one landed. Recorded after the access check, so a
+    # refused read is not counted as a pull.
+    record_rule_pulled(user_id=uid, rule_id=int(rule.id), source="mcp_get_rule")
     return await rulebooks_svc.rule_detail(uid, rule)
 
 
@@ -300,6 +315,61 @@ async def create_rule(
 ) -> dict:
     """Create a new rule in a rulebook (a SHARED rule — keep it general).
 
+    PROPOSE RULES READILY, AND WRITE ONE WHEN THE OPERATOR SAYS YES. Noticing
+    that something has hardened into a standing instruction is valuable work,
+    and a session that notices it and says nothing has thrown the observation
+    away. So raise it whenever you see one. The single step that belongs
+    between noticing and writing is the operator's yes: a rule binds every
+    future session, and they are the person it binds.
+
+    Their yes is also the only moment the rule is reliably IN FRONT of them.
+    After the write it may not be again for months — a conditional rule is not
+    read aloud at session start, and a project-scoped one does not appear in
+    an unfiltered list_rules() at all. So the proposal is the review.
+
+    When the operator asks for a rule in so many words, that IS the yes —
+    write it and move on. The loop below is for the rule you thought of.
+
+    A PROPOSAL CARRIES FOUR THINGS, and the fourth is the one that decides it:
+
+      1. WHAT it would require — the statement, in the words it would carry,
+         not a gloss of them. The operator is agreeing to text.
+      2. INTENT — what it changes about how work gets done, and what goes
+         wrong today without it. "Be careful about X" is not an intent; the
+         behaviour that would differ tomorrow is.
+      3. WHY NOW — the incident, observation or decision behind it. Pass that
+         record as arose_from_id, and say it in the conversation too: the
+         field is for the reader six months out, the sentence is for the
+         person deciding.
+      4. HOW IT WOULD BE ENFORCED — a test, a CI check, a hook, a schema
+         constraint, a duplicate gate, a review step... or nothing, in which
+         case say so plainly: "nothing — this is prose a session has to
+         remember." Answer this one honestly and it will sometimes dissolve
+         the rule, which is the point rather than a side effect. What a test
+         can assert should BE that test; a rule is what remains when nothing
+         mechanical can hold the thing. A rulebook grows by default and
+         shrinks only on purpose, so a question that prevents a rule is worth
+         more than any question that improves one's wording.
+
+    THEN CLOSE WITH A QUESTION THEY CAN ANSWER IN ONE WORD. Offer three
+    answers, and make the middle one the easy one:
+
+      * "Approve it AS WRITTEN" — you create it with the statement exactly as
+        shown. This is what makes element 1 load-bearing: they approved TEXT,
+        so that text is what gets stored, verbatim.
+      * "LET'S TALK ABOUT IT" — the wording, the scope, the tier, whether it
+        wants to be a rule at all. Most good rules arrive this way, so treat
+        this answer as the expected one rather than a setback.
+      * "NO" — let it go. If the observation is still worth keeping, it is a
+        note (create_note): recorded, findable, and binding on nobody.
+
+    Where the interface offers structured choices, ask it that way — a
+    question with named options is answered in a click, while the same
+    question inside a paragraph is answered by scrolling past. Where it does
+    not, write the three options out as three options. Either way ask once
+    and let the answer stand; re-raising a declined proposal argues a rule
+    into existence, which is the thing this whole loop exists to prevent.
+
     A rulebook rule is shared by every project that gets the rulebook: an
     always_on rulebook binds ALL your projects; a subscribed rulebook binds the
     projects that opt in. So a rulebook rule must read as a general standard —
@@ -418,6 +488,16 @@ async def create_project_rule(
     the rule is returned in get_project's applicable_rules (under
     project_rules) and in list_rules(project_id=...).
 
+    PROPOSE, THEN WRITE ON A YES — create_rule's opening carries the whole
+    loop: the four things a proposal states (what it would require, its
+    intent, why now, and how it would be enforced) and the one-word question
+    that closes it (approve as written / talk about it / no). All of it
+    applies here unchanged. Reach for that loop MORE readily on this surface,
+    not less: a project rule stays out of an unfiltered list_rules(), and a
+    conditional one stays out of session start too, so the operator's yes is
+    the one moment this rule is certain to have been seen by the person it
+    binds.
+
     Check first whether a rule is the right shape at all — create_rule's
     opening asks that question and it applies identically here. A visual
     standard is a design system; a procedure is a process (create_process);

src/scribe/mcp/tools/search.py

@@ -112,6 +112,7 @@ async def search(
         return await _search_rules(uid, q, limit)
     is_task = {"note": False, "task": True}.get(content_type)  # None => any
     t0 = time.perf_counter()
+    report: dict = {}
     raw = await semantic_search_notes(
         uid, q, limit=limit, is_task=is_task,
         project_id=project_id or None,
@@ -119,12 +120,14 @@ async def search(
         # An explicit search reaches everything the operator may read, including
         # records shared with them one-to-one.
         scope="read",
+        report=report,
     )
     record_retrieval(
         user_id=uid, source="mcp_search", query=q,
         threshold=DEFAULT_SIMILARITY_THRESHOLD, limit=limit,
         project_id=project_id or None, is_task=is_task, results=raw,
         duration_ms=(time.perf_counter() - t0) * 1000.0,
+        best_available=report.get("best_available_score"),
     )
     owners = await owner_names_for(
         {int(note.user_id) for _s, note in raw if note.user_id != uid}
@@ -158,17 +161,54 @@ async def retrieval_telemetry(days: int = 30) -> dict:
     hand-probing the live instance, which is how the last such decision had to
     be made.
 
-    Two readouts, from the two tables built for them:
+    Three readouts, from the three tables built for them:
 
     `sources` — per retrieval surface (`auto_inject`, `write_path`,
     `mcp_search`, …), from `retrieval_logs`: `calls`, `zero_result_calls`,
-    `cleared_threshold` (how often the best hit beat the threshold in force for
-    that call), the `top_score` spread (p10/p50/p90/min/max), `avg_result_count`
-    and `p90_duration_ms`. THE number to read first is `cleared_threshold`
-    against `calls`, with the spread beside it: a surface that clears its bar
-    on nearly every call is either well-tuned or too loose, and p10 says which.
+    `near_misses`, the `top_score` spread (p10/p50/p90/min/max),
+    `avg_result_count` and `p90_duration_ms`.
 
-    `usage` — from `note_usage_events`, at the per-note grain
+    THE NUMBER TO READ FIRST IS `near_misses.p90`, AGAINST THE THRESHOLD IN
+    FORCE FOR THAT SURFACE. It is measured on the calls the BAR turned away —
+    zero-result calls, minus the ones whose zero was a repeat the reader had
+    already been shown — using the best score the ranker reached before the bar
+    rejected it. So it is the one figure here that says something the bar
+    cannot make true by construction, and `max` is always below the threshold:
+    an above-bar candidate nobody excluded would have been returned. A bar at 0.72 turning away a stream of 0.71s is set too
+    high by a hair and the surface is losing hits it should have had. The same
+    bar turning away 0.30s is working, and the corpus simply had nothing. Both
+    render as a zero-result call, and nothing else in this readout tells them
+    apart.
+
+    `near_misses` is `null` when no declining call in the window measured it —
+    rows written before #3670 shipped cannot know. That is "not measured", not
+    "nothing came close"; a 0.0 there would be a claim about the corpus
+    invented out of a caller's silence.
+
+    THERE IS NO `cleared_threshold` ANY MORE, and if you remember one, that
+    memory is of a tautology (#3670). The search applies the bar before
+    returning, so every returned result cleared it by construction and a call
+    with no results has no score to compare: the field was true exactly when
+    `result_count > 0`, i.e. it was `calls - zero_result_calls` under a name
+    that promised a second opinion. `zero_result_calls + cleared_threshold ==
+    calls` held on all nineteen readings ever taken. The reading procedure
+    built on it — "clears its bar on nearly every call" — asked you to compare
+    a number with itself.
+
+    CHECK `suppression` BEFORE CONCLUDING ANYTHING FROM `zero_result_calls`. A
+    zero-result call is two different events wearing one number: the ranker
+    found nothing above the bar, or it found only what this session had already
+    been shown. Just the first is evidence about the bar. `suppression` splits
+    them where the surface can tell — `zero_because_already_shown` comes off
+    `zero_result_calls` to leave the true ranker declines.
+
+    `suppression` is `null` when NO row in the window reported it, and that is
+    "not measured here", NOT "none suppressed". Surfaces that pass their
+    exclusions into the search never see what was dropped, so they cannot say.
+    Do not read a null as a zero: reading an artifact as a measurement is how
+    this surface got mis-scoped once already (#3311, #3497).
+
+    `usage` — NOTES ONLY, from `note_usage_events`, at the per-note grain
     `retrieval_logs` cannot be indexed at: `surfaced` (ranked surfacings — a
     scored surface CHOSE the record), `ambient` (the rest), `pulled` split into
     `pulled_by_agent` / `pulled_by_human`, the distinct-note counts, and
@@ -182,6 +222,84 @@ async def retrieval_telemetry(days: int = 30) -> dict:
     tuned against — only by a pull the agent made. Aggregating across the
     mcp_/rest_ prefix would silently answer the wrong one.
 
+    `usage["by_source"]` — THE number to tune a threshold against, because the
+    top-level `pull_through` is a corpus average and averages the surfaces
+    together. Per surface: `notes_surfaced`, `notes_pulled`, `pull_through`,
+    and `ambient: true` on surfaces whose surfacings were not scored choices
+    (their ratio is null — "surfaced often, opened never" is not a judgment
+    about a record nothing chose). Read it as: of the distinct notes THIS
+    surface put in front of the agent, how many did the agent then open?
+
+It is an UPPER BOUND per surface: a pull records the door it came
+    through, not the surface that led there, so a note surfaced by two surfaces
+    and opened once counts for both — attribution would need the session
+    identity #2085 declined to invent. `by_source_failed: true` means that one
+    query failed while the rest of the readout stood.
+
+    `rule_usage` — the same question for RULES, from `rule_usage_events`:
+    `surfaced` and `ambient`, `pulled` split into `pulled_by_agent` /
+    `pulled_by_human`, the distinct-rule counts, and `pull_through` on the same
+    definition (agent pulls over RANKED surfacings).
+
+    A SEPARATE BLOCK, not folded into `usage`, and reading it as one number
+    with that is the mistake to avoid. The corpora differ by orders of
+    magnitude — a few dozen eligible rules against thousands of notes — so a
+    blended ratio would be the note ratio with noise on it and would hide the
+    rule arm entirely.
+
+    `surfaced` VS `ambient` IS THE READING THAT MATTERS HERE. `surfaced` counts
+    rules a ranker chose — today only the write-path arm — and those are claims
+    a pull can settle. `ambient` counts BULK DELIVERIES: the SessionStart
+    preload, `list_always_on_rules`, and the `rules_payload` surfaces
+    (`enter_project`, `get_project`, `get_milestone`, `start_planning`,
+    `get_task`), which hand over the whole applicable set at once with nobody
+    choosing anything. A large `ambient` says the resident set is big and
+    arrives often — never that it is useful, and never that it is read.
+
+    `pull_through` therefore divides by `surfaced` alone. Fold the preload in
+    and growing the always-on set would depress the arm's measured precision
+    while trimming it would flatter it, for reasons having nothing to do with
+    the arm. To judge the PRELOAD instead, compare `ambient` against pulls of
+    those same rules over time: a resident set surfaced thousands of times and
+    opened never is the dead-weight signal, one tier up.
+
+    Read it against `sources["write_path_rule"]`. That arm was once believed
+    never to decline — the reading that scoped #3311 — but it was the arm's
+    `retrieval_logs` row being written only on calls that FOUND something, so
+    the zeros were missing rather than absent (#3497). Measured since, it
+    declines the large majority of its calls like any other surface.
+
+    EVERY COUNTER BLOCK CARRIES ITS OWN COVERAGE — `complete_from` and
+    `covers_window`. `complete_from` is when the number became trustworthy:
+    for one source, its first recorded row; for a section that sums several,
+    the LATEST of theirs, because a total is complete only once every
+    contributor was being written. `covers_window: false` means the window
+    reaches back further than the recording does, so the count is a fraction
+    of the period it appears to describe.
+
+    READ IT BEFORE COMPARING TWO NUMBERS, and especially before comparing
+    across a deploy. A counter added last week, read over a 30-day window,
+    reports a real count against an imagined denominator — and the result is
+    a plausible fraction rather than an obvious zero, which is what makes it
+    dangerous. That reading cost milestone #379 five steps aimed at a defect
+    that did not exist.
+
+    `covers_window` is null, never false, when nothing was ever recorded:
+    "no measurement" is not "partial measurement", the same distinction
+    `suppression`'s null carries a few paragraphs up.
+
+    A SOURCE SHOWING `calls: 0` WAS RECORDING AND MADE NO CALLS. `sources`
+    lists every source the table has ever held, not only those active in the
+    window, so a surface that stopped firing stays visible rather than
+    disappearing — being absent is reserved for a source that has never
+    recorded at all. Its score fields are null, not zero: the calls are a
+    real observation, the distribution is not one.
+
+    `rule_usage_failed: true` means that read failed while the rest of the
+    readout stood. The counts are still present so a caller can render, but
+    they are zeros meaning "could not find out", not "nothing happened" — do
+    not report a pull-through from a block carrying that flag.
+
     Scoped to your own telemetry — a retrieval log records what your agent
     asked for, query text included, and is not a shared record kind.
 

src/scribe/mcp/tools/tasks.py

@@ -103,7 +103,7 @@ async def get_task(task_id: int) -> dict:
         applicable = await rulebooks_svc.get_applicable_rules(
             project_id=note.project_id, user_id=uid,
         )
-        data.update(rulebooks_svc.rules_payload(applicable))
+        data.update(rulebooks_svc.rules_payload(applicable, user_id=uid, source="get_task"))
     data.update(await access_svc.describe_provenance(uid, note))
     # Same reasoning as get_note's record_pulled, and this is the tool where it
     # matters MOST: auto-inject ranks kind-blind over a corpus that is

src/scribe/models/__init__.py

@@ -28,6 +28,7 @@ from scribe.models.invitation import InvitationToken  # noqa: E402, F401
 from scribe.models.embedding import NoteEmbedding, RuleEmbedding  # noqa: E402, F401
 from scribe.models.retrieval_log import RetrievalLog  # noqa: E402, F401
 from scribe.models.note_usage import NoteUsageEvent  # noqa: E402, F401
+from scribe.models.rule_usage import RuleUsageEvent  # noqa: E402, F401
 from scribe.models.project import Project  # noqa: E402, F401
 from scribe.models.milestone import Milestone  # noqa: E402, F401
 from scribe.models.task_log import TaskLog  # noqa: E402, F401

src/scribe/models/retrieval_log.py

@@ -42,8 +42,26 @@ class RetrievalLog(Base):
     # False=notes, NULL=any.
     is_task: Mapped[bool | None] = mapped_column(Boolean, nullable=True)
     result_count: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
+    # How many scored hits this call DROPPED because the session had already
+    # been shown them. NULLABLE, and the null is load-bearing: it means "this
+    # surface does not report suppression", which must not read as "nothing was
+    # suppressed". `result_count == 0` alone conflates two different events —
+    # the ranker found nothing above threshold, and the ranker found something
+    # the reader already had — and only the first says a threshold is too high.
+    # Reading a zero as a ranker decline is how #3311 mis-scoped a milestone;
+    # an unmeasured value that renders as 0 is the same mistake with a nicer
+    # face, so surfaces that filter INSIDE the search leave this null.
+    suppressed_count: Mapped[int | None] = mapped_column(Integer, nullable=True)
     top_score: Mapped[float | None] = mapped_column(Float, nullable=True)
     min_score: Mapped[float | None] = mapped_column(Float, nullable=True)
+    # The best score the ranker COULD have offered, before the threshold — as
+    # against `top_score`, which is the best it DID offer. They are equal on
+    # any call that returned something, and only this one exists on a call
+    # that returned nothing, which is the only place a bar can be judged from
+    # (#3670). Null means the caller did not measure it, never "nothing was
+    # close": a 0.0 there would read as a corpus with no relevant records at
+    # all, which is an artifact standing in for a measurement.
+    best_available_score: Mapped[float | None] = mapped_column(Float, nullable=True)
     # [{"id": int, "score": float, "rank": int}, ...], highest-first.
     result_ids: Mapped[list] = mapped_column(JSONB, nullable=False, default=list)
     duration_ms: Mapped[float | None] = mapped_column(Float, nullable=True)
@@ -67,6 +85,7 @@ class RetrievalLog(Base):
             "project_id": self.project_id,
             "is_task": self.is_task,
             "result_count": self.result_count,
+            "suppressed_count": self.suppressed_count,
             "top_score": self.top_score,
             "min_score": self.min_score,
             "result_ids": self.result_ids,

src/scribe/models/rule_usage.py

@@ -0,0 +1,95 @@
+from sqlalchemy import BigInteger, Index, Text
+from sqlalchemy.orm import Mapped, mapped_column
+
+from scribe.models import Base
+from scribe.models.base import CreatedAtMixin, iso
+
+SURFACED = "surfaced"
+PULLED = "pulled"
+
+
+class RuleUsageEvent(Base, CreatedAtMixin):
+    """One row per time a rule was SURFACED to the agent, or PULLED in full.
+
+    The sibling `note_usage_events` has had since 2026-07, third in the line
+    after `rule_embeddings` and `rule_versions` — and, like those, it exists
+    because the rule side kept inheriting machinery built for notes and
+    quietly getting the weaker version of it.
+
+    WHY RULES NEED THEIR OWN AND CANNOT SHARE THE NOTE TABLE. Not squeamishness
+    about a polymorphic column — the row shares no note-specific fields and the
+    aggregate readout is the same shape, which is the strongest case for
+    sharing that note #3163 admits. What decides it is IDENTITY AT RESTORE. A
+    note id and a rule id are different namespaces resolved through different
+    maps, and `note_usage_events`'s importer maps `note_id` through
+    `note_id_map` and drops what does not resolve. A rule id parked in that
+    column would come back from a backup silently reattached to whatever note
+    happened to take that number — telemetry that is not merely lost but wrong,
+    and wrong in a way nothing downstream could detect.
+
+    WHAT THIS MEASURES, AND WHY IT DID NOT EXIST. The write-path standing-rule
+    arm is the only retrieval surface in Scribe whose usefulness cannot be
+    observed — and, not coincidentally, the only one that has never declined to
+    fire (#3311: 296 calls, zero zero-result, 100% clearing its threshold).
+    `retrieval_logs` gives it scores; scores say what the ranker thought, never
+    whether the hint landed. Without a pull counter no install can tune the arm
+    from evidence, only from the shape of a histogram.
+
+    Deliberately FK-FREE on `rule_id` and `user_id`, matching `note_usage_events`,
+    `retrieval_logs` and `app_logs` — and diverging from `rule_versions`, which
+    does carry FKs. The difference is what the row is FOR: a version is part of
+    a rule's history and dies with it, while telemetry outlives the row it
+    describes. Deleting a rule must not erase the evidence that it was surfaced
+    forty times and opened never, because that evidence is precisely the case
+    for having deleted it.
+
+    Cells left deliberately empty (note #3163's step 3): no share ACL — rules
+    have none of their own; no soft delete — nothing restores a telemetry row,
+    and the table is append-only; no embedding — an event is not a document.
+    """
+
+    __tablename__ = "rule_usage_events"
+
+    # BigInteger throughout, where the note twin uses Integer. `rule_id` has to
+    # be, since `rules.id` is BigInteger — and once one column is, matching the
+    # rest costs nothing and keeps the row uniform. A high-churn append-only
+    # telemetry table is a poor place to discover an id ceiling.
+    id: Mapped[int] = mapped_column(BigInteger, primary_key=True)
+    user_id: Mapped[int | None] = mapped_column(BigInteger, nullable=True)
+    rule_id: Mapped[int] = mapped_column(BigInteger, nullable=False)
+
+    # 'surfaced' | 'pulled'
+    event: Mapped[str] = mapped_column(Text, nullable=False)
+
+    # Which surface produced it. A CONVENTION, not a fixed vocabulary, and the
+    # note twin's comment explains why this one deliberately does not enumerate
+    # its members: the previous such list went stale, naming a source nothing
+    # wrote while omitting ones that existed, and a half-true enumeration reads
+    # as authoritative in exactly the way that misleads (#2476).
+    # `grep -rn record_rule_pulled\|record_rule_surfaced src/` is the
+    # authoritative list, and unlike a comment it cannot drift.
+    #
+    # The mcp_/rest_ prefix split is load-bearing here for the same reason it is
+    # for notes, and more so: "is this rule dead weight?" is served by any pull,
+    # but "did that injected hint land?" — the question this arm exists to
+    # answer — is served by AGENT pulls only. Never aggregate across the prefix
+    # without saying why.
+    source: Mapped[str] = mapped_column(Text, nullable=False)
+
+    __table_args__ = (
+        # Every readout is "these rule ids, split by event" — a covering
+        # composite beats separate single-column indexes for it.
+        Index("ix_rule_usage_rule_event", "rule_id", "event"),
+        Index("ix_rule_usage_created_at", "created_at"),
+        Index("ix_rule_usage_user_id", "user_id"),
+    )
+
+    def to_dict(self) -> dict:
+        return {
+            "id": self.id,
+            "created_at": iso(self.created_at),
+            "user_id": self.user_id,
+            "rule_id": self.rule_id,
+            "event": self.event,
+            "source": self.source,
+        }

src/scribe/routes/api.py

@@ -10,6 +10,61 @@ async def health():
     return jsonify({"status": "ok"})
 
 
+def build_version_payload() -> dict:
+    """What build is this, separated into the values that answer different
+    questions (rule 149).
+
+    UNTIL 2026-08-31 THIS RETURNED THE CHANNEL. `BUILD_VERSION` in CI was
+    literally "dev" / "main" / the tag, so a running instance reported
+    `{"version": "main"}` — a channel name sitting where a build identifier
+    belongs. The cost was concrete: with a deploy misbehaving, nothing on the
+    instance could say which commit was serving it, and the one endpoint whose
+    job that is answered with the name of a branch.
+
+    The three values, and why they are three:
+
+    - `version` — the NAME, `YYYY.MM.DD.HHMM` from COMMIT time. Answers "is
+      this the same code?", so two channels carrying one commit report the
+      same string.
+    - `build` — the ORDERING KEY, minutes since 2020-01-01 from BUILD time.
+      Answers "may this be installed over that?". The ONLY value anything may
+      compare; it is monotonic by construction, which neither a commit count
+      (branches diverge) nor a commit time (rebuilds go backwards) is.
+    - `channel` — its own field, never folded into the name.
+
+    Plus `commit`, so the artifact's claim about itself can be checked against
+    the `:<sha>` it was published under (rule 145).
+
+    ABSENT RATHER THAN EMPTY when unknown. A local build has no ordering key
+    and no channel, and saying so is honest; emitting `""` or a placeholder
+    would let it claim a position in an update order it is not part of. A
+    reader must treat a missing `build` as "cannot be ordered", not as zero.
+    """
+    payload: dict = {"version": os.environ.get("APP_VERSION", "dev")}
+
+    # Reported verbatim, never validated against an enum — a build claiming
+    # something unexpected is better shown than dropped (rule 149).
+    for key, env in (("channel", "APP_CHANNEL"), ("commit", "APP_COMMIT")):
+        value = (os.environ.get(env) or "").strip()
+        if value:
+            payload[key] = value
+
+    raw_key = (os.environ.get("APP_BUILD_KEY") or "").strip()
+    if raw_key:
+        try:
+            # An INTEGER, not a string. A string ordering key is how a
+            # comparison silently becomes lexicographic — "9" > "10" — which
+            # is the same class of fault as folding the channel in: it reads
+            # fine and orders wrong.
+            payload["build"] = int(raw_key)
+        except ValueError:
+            # A malformed key is omitted rather than passed through: a reader
+            # that cannot order is correct, one that orders on garbage is not.
+            pass
+
+    return payload
+
+
 @api.route("/version")
 async def version():
-    return jsonify({"version": os.environ.get("APP_VERSION", "dev")})
+    return jsonify(build_version_payload())

src/scribe/routes/plugin.py

@@ -101,6 +101,46 @@ async def autoinject_retrieve():
     return jsonify(result)
 
 
+@plugin_bp.get("/tool-rules")
+@login_required
+async def pre_tool_rules():
+    """Standing rules for the plugin's PreToolUse hook on ACTIONS (#3476).
+
+    Answers "does a recorded rule speak to the command about to be run?" — the
+    sibling of /prior-art, which can only answer that question about a code
+    write. Rules about which tool to reach for (don't curl the forge, don't
+    stand up a stack, don't run the suite locally) had no retrieval surface at
+    all before this, which is why they all had to live in the resident preload.
+
+    Titles + trigger only, never the statement: the hint says a rule may apply
+    and hands over `get_rule(id)`. One rule at most (RULEHINT_LIMIT), and empty
+    most of the time.
+
+    Query:
+        tool (str)              — the tool about to run, e.g. `Bash`. Used in
+                                  the hint's wording, not in the search: a
+                                  rule is about the action, not the harness.
+        command (str)           — the command about to run; the semantic query.
+                                  Absent or blank → empty, no search.
+        repo (optional)         — working repo remote, resolved to the bound
+                                  project exactly as /retrieve and /prior-art.
+        exclude_rule_ids (opt)  — comma-separated rule ids already surfaced
+                                  this session. SHARED with /prior-art's
+                                  ledger on purpose: one session keeps one
+                                  list, so a rule named by either arm is not
+                                  re-offered by the other.
+    """
+    tool = (request.args.get("tool") or "tool").strip()
+    command = request.args.get("command") or ""
+    project_id, _repo, _unbound = await _project_scope()
+    exclude_rule_ids = _int_list(request.args.get("exclude_rule_ids"))
+    result = await plugin_ctx_svc.build_tool_rule_hint(
+        g.user.id, tool, command,
+        project_id=project_id, exclude_rule_ids=exclude_rule_ids,
+    )
+    return jsonify(result)
+
+
 @plugin_bp.get("/prior-art")
 @login_required
 async def write_path_prior_art():

src/scribe/routes/rulebooks.py

@@ -10,6 +10,9 @@ from quart import Blueprint, jsonify, request
 from scribe.auth import get_current_user_id, login_required
 import scribe.services.rulebooks as rulebooks_svc
 from scribe.services.trash import delete as trash_delete
+from scribe.services.rule_usage import (
+    empty_rule_usage, record_rule_pulled, usage_for_rules,
+)
 
 rulebooks_bp = Blueprint("rulebooks", __name__, url_prefix="/api")
 
@@ -136,13 +139,24 @@ async def list_rules():
     except ValueError:
         return jsonify({"error": "rulebook_id, topic_id, project_id must be integers"}), 400
 
+    uid = get_current_user_id()
     rows = await rulebooks_svc.list_rules(
-        user_id=get_current_user_id(),
+        user_id=uid,
         rulebook_id=rulebook_id,
         topic_id=topic_id,
         project_id=project_id,
     )
-    return jsonify({"rules": [r.to_dict() for r in rows]})
+    items = [r.to_dict() for r in rows]
+    # One aggregate for the whole page — a per-row lookup here would be N+1 by
+    # construction, the same reason the snippet list does it this way. Every
+    # row gets the key, zero-filled, so the UI renders "never surfaced" rather
+    # than having to treat a missing field as a state. That matters more here
+    # than for snippets: every rule on every install predates this table, so
+    # for a while the zero-filled shape IS the common case.
+    usage = await usage_for_rules([int(it["id"]) for it in items])
+    for it in items:
+        it["usage"] = usage.get(int(it["id"]), empty_rule_usage())
+    return jsonify({"rules": items})
 
 
 @rulebooks_bp.post("/rulebook-topics/<int:topic_id>/rules")
@@ -182,6 +196,11 @@ async def get_rule(rule_id: int):
     rule = await rulebooks_svc.get_rule(rule_id, uid)
     if rule is None:
         return jsonify({"error": "rule not found"}), 404
+    # `rest_` rather than `mcp_`, and the prefix is load-bearing: "is this rule
+    # dead weight?" is served by any pull, but "did that injected hint land?"
+    # — the question this arm exists to answer — is served by AGENT pulls only.
+    # A person clicking through the rule list says nothing about the hint.
+    record_rule_pulled(user_id=uid, rule_id=int(rule.id), source="rest_rule")
     return jsonify(await rulebooks_svc.rule_detail(uid, rule))
 
 

src/scribe/routes/search.py

@@ -44,17 +44,20 @@ async def search_route():
     project_id = request.args.get("project_id", type=int)
 
     t0 = time.perf_counter()
+    report: dict = {}
     results = await semantic_search_notes(
         uid, q, limit=limit, is_task=is_task, threshold=_REST_SEARCH_THRESHOLD,
         project_id=project_id, system_id=system_id,
         # The user typed this, so it reaches everything they may read.
         scope="read",
+        report=report,
     )
     record_retrieval(
         user_id=uid, source="rest_search", query=q,
         threshold=_REST_SEARCH_THRESHOLD, limit=limit,
         project_id=project_id, is_task=is_task, results=results,
         duration_ms=(time.perf_counter() - t0) * 1000.0,
+        best_available=report.get("best_available_score"),
     )
     owners = await owner_names_for(
         {int(note.user_id) for _s, note in results if note.user_id != uid}

src/scribe/services/background.py

@@ -6,20 +6,63 @@ write that never errors and never lands (the #2663 GC footgun). This module is
 the one place that gets the pattern right: strong references in ``_pending``,
 discarded on completion, with failures logged at WARNING instead of vanishing.
 
-``note_usage`` and ``retrieval_telemetry`` predate this module and carry their
-own copies with bespoke canary semantics; new fire-and-forget callers use this
-instead of writing a fourth copy.
+``retrieval_telemetry`` predates this module and keeps its own copy, because
+its canary is a genuinely different shape — one process-wide flag and no
+AppLog row. ``note_usage`` and ``rule_usage`` share ``report_telemetry_failure``
+below. New fire-and-forget callers use ``spawn`` rather than writing another
+copy of the strong-reference dance.
 """
 from __future__ import annotations
 
 import asyncio
 import logging
+import traceback
 from collections.abc import Coroutine
 
 logger = logging.getLogger(__name__)
 
 _pending: set[asyncio.Task] = set()
 
+# Sites that have already dropped their once-per-process AppLog row, keyed
+# "<subsystem>:<site>". A readout can run on every list render — without this,
+# a broken table turns the error log into a firehose that buries the finding it
+# exists to surface.
+_reported: set[str] = set()
+
+
+async def report_telemetry_failure(subsystem: str, site: str) -> None:
+    """Make a swallowed telemetry failure visible. Call from an except block.
+
+    WARNING to the process log every time; one AppLog error row per process per
+    (subsystem, site) so the admin UI shows the outage without host access.
+
+    THIS IS NOT DECORATION. #2663 is the record of a telemetry subsystem running
+    at zero for weeks — every counter reading empty, indistinguishable from
+    "nobody uses this" — because every failure went to ``logger.debug``. A
+    subsystem whose failures are all invisible cannot report its own death.
+
+    The AppLog write is itself guarded: when the database is down it fails too,
+    and that is fine. The WARNING already said so, and a canary must never take
+    down the surface it watches.
+    """
+    logger.warning("%s telemetry %s failed", subsystem, site, exc_info=True)
+    key = f"{subsystem}:{site}"
+    if key in _reported:
+        return
+    _reported.add(key)
+    try:
+        from scribe.services.logging import log_error
+
+        await log_error(
+            endpoint=subsystem,
+            error_type=f"{subsystem}_{site}_failed",
+            error_message=f"{subsystem} telemetry {site} is failing; "
+            "usage counters will read zero until this is fixed",
+            traceback=traceback.format_exc(),
+        )
+    except Exception:
+        logger.debug("%s canary write failed", subsystem, exc_info=True)
+
 
 def spawn(coro: Coroutine, *, site: str) -> None:
     """Schedule ``coro`` fire-and-forget; ``site`` names it in failure logs.

src/scribe/services/backup.py

@@ -12,6 +12,7 @@ from scribe.models.note_version import NoteVersion
 from scribe.models.rule_version import RuleVersion
 from scribe.models.design_system import DesignSystem, DesignToken
 from scribe.models.note_usage import NoteUsageEvent
+from scribe.models.rule_usage import RuleUsageEvent
 from scribe.models.canonical_system import CanonicalSystem
 from scribe.models.rulebook import RuleRelation, rule_systems as rule_systems_t
 from scribe.models.code_shape import CodeShape, CodeShapeEvent, CodeShapeUse
@@ -62,8 +63,12 @@ logger = logging.getLogger(__name__)
 # _COLUMN_EXCLUSIONS and its guard landed with it, so the next such column
 # fails the build instead.
 # v13 (2026-08) added rule_versions — a rule's edit history (milestone 323).
+# v14 (2026-09) added rule_usage_events — the rule twin of note_usage_events
+# (milestone 333). Carrying it is the WHOLE REASON the table is separate: the
+# note importer maps note_id through note_id_map, so a rule id parked there
+# would restore attached to whatever note took that number.
 # Bump when the serialized schema changes.
-BACKUP_VERSION = 13
+BACKUP_VERSION = 14
 
 # Every table this backup carries, by its REAL name. Paired with _NOT_INCLUDED
 # below, these two lists must together account for the entire schema — which is
@@ -92,6 +97,11 @@ _BACKED_UP = [
     # v13 (2026-08): a rule's edit history (milestone 323). note_versions has
     # always travelled; its sibling has no excuse not to.
     "rule_versions",
+    # v14 (2026-09): rule usage telemetry (milestone 333). Same argument
+    # note_usage_events makes for itself — pull-through is only ever
+    # accumulated, so a restore that dropped it would silently reset the
+    # measurement to zero while everything still looked fine.
+    "rule_usage_events",
 ]
 
 # Tables intentionally NOT in the backup, surfaced in the payload so the gap is
@@ -178,6 +188,8 @@ _COLUMN_EXCLUSIONS: dict[str, set[str]] = {
     "note_supersessions": {"id", "created_at"},
     "rule_relations": {"id", "created_at"},
     "note_usage_events": {"id"},
+    # Same as the note twin: the surrogate key is re-issued on insert.
+    "rule_usage_events": {"id"},
     "design_systems": {"deleted_at", "deleted_batch_id", "created_at", "updated_at"},
     "design_tokens": {"deleted_at", "deleted_batch_id", "created_at", "updated_at"},
     "repo_bindings": {"id", "created_at", "updated_at"},
@@ -321,6 +333,17 @@ def _usage_event_rows(rows) -> list[dict]:
     ]
 
 
+def _rule_usage_event_rows(rows) -> list[dict]:
+    return [
+        {
+            "user_id": r.user_id, "rule_id": r.rule_id, "event": r.event,
+            "source": r.source,
+            "created_at": r.created_at.isoformat() if r.created_at else None,
+        }
+        for r in rows
+    ]
+
+
 def _code_shape_rows(rows) -> list[dict]:
     return [r.to_dict() for r in rows]
 
@@ -606,6 +629,9 @@ async def export_full_backup() -> dict:
         )).scalars().all()
         design_tokens = (await session.execute(select(DesignToken))).scalars().all()
         usage_events = (await session.execute(select(NoteUsageEvent))).scalars().all()
+        rule_usage_events = (
+            await session.execute(select(RuleUsageEvent))
+        ).scalars().all()
         repo_bindings = (await session.execute(select(RepoBinding))).scalars().all()
         code_shapes = (await session.execute(select(CodeShape))).scalars().all()
         code_shape_events = (await session.execute(
@@ -665,6 +691,7 @@ async def export_full_backup() -> dict:
         "design_systems": _design_system_rows(design_systems),
         "design_tokens": _design_token_rows(design_tokens),
         "note_usage_events": _usage_event_rows(usage_events),
+        "rule_usage_events": _rule_usage_event_rows(rule_usage_events),
         "repo_bindings": _repo_binding_rows(repo_bindings),
         "note_supersessions": _note_supersession_rows(supersessions),
         "code_shapes": _code_shape_rows(code_shapes),
@@ -791,6 +818,14 @@ async def export_user_backup(user_id: int) -> dict:
             select(RuleVersion).where(RuleVersion.rule_id.in_(_rule_ids))
             .order_by(RuleVersion.rule_id, RuleVersion.id)
         )).scalars().all() if _rule_ids else []
+        # Scoped through the RULE for the same reason the versions above are,
+        # and it is worth restating because the column that looks right is
+        # wrong: `user_id` here is whoever the arm fired FOR, not who owns the
+        # rule. Filtering on it would carry this user's surfacings of someone
+        # ELSE's rule and drop the ones fired for someone else on theirs.
+        rule_usage_events = (await session.execute(
+            select(RuleUsageEvent).where(RuleUsageEvent.rule_id.in_(_rule_ids))
+        )).scalars().all() if _rule_ids else []
         rule_relations = (await session.execute(
             select(RuleRelation).where(
                 RuleRelation.from_rule_id.in_(_rule_ids),
@@ -858,6 +893,7 @@ async def export_user_backup(user_id: int) -> dict:
         "design_systems": _design_system_rows(design_systems),
         "design_tokens": _design_token_rows(design_tokens),
         "note_usage_events": _usage_event_rows(usage_events),
+        "rule_usage_events": _rule_usage_event_rows(rule_usage_events),
         "repo_bindings": _repo_binding_rows(repo_bindings),
         "note_supersessions": _note_supersession_rows(supersessions),
         "code_shapes": _code_shape_rows(code_shapes),
@@ -994,7 +1030,8 @@ async def _restore_v2(data: dict) -> dict:
         "rulebook_subscriptions": 0, "rule_suppressions": 0,
         "topic_suppressions": 0, "rulebook_exclusions": 0,
         "systems": 0, "record_systems": 0, "design_systems": 0,
-        "design_tokens": 0, "note_usage_events": 0, "repo_bindings": 0,
+        "design_tokens": 0, "note_usage_events": 0, "rule_usage_events": 0,
+        "repo_bindings": 0,
         "note_supersessions": 0, "code_shapes": 0, "code_shape_events": 0,
         "code_shape_uses": 0, "canonical_systems": 0,
         "rule_systems": 0, "rule_relations": 0, "rule_versions": 0,
@@ -1496,6 +1533,25 @@ async def _restore_v2(data: dict) -> dict:
             ))
             stats["note_usage_events"] += 1
 
+        # The rule twin — and the reason it is a separate table at all.
+        # Resolved through rule_id_map, NOT note_id_map. A rule id run through
+        # the note map would either drop (best case) or land on whatever note
+        # took that number, producing telemetry that is wrong rather than
+        # missing and that nothing downstream could detect (milestone 333).
+        # Must come after the rules themselves; rule_id_map is populated there.
+        for ev in data.get("rule_usage_events", []):
+            mapped_rid = rule_id_map.get(ev.get("rule_id", 0))
+            if mapped_rid is None:
+                continue
+            session.add(RuleUsageEvent(
+                user_id=user_id_map.get(ev.get("user_id") or 0),
+                rule_id=mapped_rid,
+                event=ev.get("event", ""),
+                source=ev.get("source", ""),
+                created_at=_dt(ev.get("created_at")),
+            ))
+            stats["rule_usage_events"] += 1
+
         # 20. Repo bindings — small, but losing them means every bound repo
         # quietly stops loading its project at session start.
         for rb_data in data.get("repo_bindings", []):

src/scribe/services/embeddings.py

@@ -344,6 +344,52 @@ def chunk_document(title: str | None, body: str | None) -> list[str]:
     return chunks
 
 
+async def _claim_parent_row(session, id_column, row_id: int, label: str) -> bool:
+    """Lock the record a vector belongs to BEFORE rewriting that vector (#3262).
+
+    An embedding write and a cascading delete of the same record take the same
+    two row locks in OPPOSITE orders. The embedder deletes the old chunk rows
+    and then, on INSERT, needs the foreign key's lock on the parent; a delete
+    of the parent — or of the rulebook, topic or project above it — locks the
+    parent first and cascades down into the chunk rows. That is a cycle, and
+    Postgres breaks it by killing one side at random: sometimes the embedding
+    write, which is swallowed and invisible, and sometimes the operator's
+    delete, which surfaces as a 500 on an operation that should have worked.
+
+    Claiming the parent first REMOVES the cycle rather than narrowing it.
+    Either the embedder arrives first and the delete waits its turn behind it,
+    or the delete already holds the row and NOWAIT makes the embedder lose at
+    once. The embedder is the side that should lose: a skipped refresh costs a
+    stale vector until the next write or the startup backfill, and the other
+    outcome costs a person their request.
+
+    FOR KEY SHARE, not FOR UPDATE — it is precisely the lock the INSERT's
+    foreign key would take anyway, so it conflicts with a delete of the parent
+    and with nothing else. An ordinary edit of the same record, or a second
+    refresh racing this one, is unaffected.
+
+    Returns False when the row is locked or already gone; the caller skips.
+    """
+    try:
+        held = (await session.execute(
+            select(id_column)
+            .where(id_column == row_id)
+            # BOTH flags: SQLAlchemy spells the four Postgres row locks as a
+            # read/key_share pair, and key_share alone is FOR NO KEY UPDATE —
+            # which would make two refreshes of one record fight each other.
+            .with_for_update(read=True, key_share=True, nowait=True)
+        )).scalar_one_or_none()
+    except Exception:
+        # LockNotAvailable: this record is being deleted right now. Not an
+        # error — the delete wins by design.
+        logger.debug("Skipping embedding for %s %d — row is being deleted", label, row_id)
+        return False
+    if held is None:
+        logger.debug("Skipping embedding for %s %d — row is gone", label, row_id)
+        return False
+    return True
+
+
 async def upsert_note_embedding(
     note_id: int, user_id: int, title: str | None, body: str | None
 ) -> None:
@@ -380,6 +426,8 @@ async def upsert_note_embedding(
 
     try:
         async with async_session() as session:
+            if not await _claim_parent_row(session, Note.id, note_id, "note"):
+                return
             await session.execute(
                 delete(NoteEmbedding).where(NoteEmbedding.note_id == note_id)
             )
@@ -400,6 +448,23 @@ async def upsert_note_embedding(
         logger.warning("Failed to persist embedding for note %d", note_id, exc_info=True)
 
 
+# Both searches rank WITHOUT the threshold and apply it in Python, so the best
+# rejected score stays observable (#3670). The qualifying set is provably
+# unchanged: rows arrive ordered by distance ascending, so every above-bar row
+# sorts ahead of every below-bar one, and an over-fetch that used to return N
+# above-bar rows returns the same N plus some losers. What changes is only that
+# the losers are now visible instead of discarded inside the query.
+#
+# That visibility is the entire point. A bar can only be judged from the calls
+# it TURNED AWAY — a 0.72 bar rejecting a stream of 0.71s is set too high by a
+# hair, one rejecting 0.30s is working — and those two are indistinguishable
+# from any arrangement of the columns that survive the filter.
+#
+# `report` is how the score gets out without changing what a search RETURNS.
+# Eight of the eleven call sites want hits and nothing else; the three that
+# write telemetry pass a dict and read `best_available_score` back out of it.
+
+
 async def semantic_search_notes(
     user_id: int,
     query: str,
@@ -414,12 +479,19 @@ async def semantic_search_notes(
     scope: str = "own",
     demote_superseded: bool = True,
     system_id: int | None = None,
+    report: dict | None = None,
 ) -> list[tuple[float, Note]]:
     """Return up to *limit* (score, note) pairs most relevant to *query*.
 
     Scores are cosine similarities in [-1, 1]; only notes at or above
     *threshold* are returned, sorted highest-first.
 
+    Pass `report` (an empty dict) to learn what the threshold turned away:
+    the function sets `report["best_available_score"]` to the highest score
+    anything reached, or None when the corpus offered nothing at all. It is
+    the only figure that survives a call returning nothing, and therefore the
+    only one a bar can be judged from (#3670).
+
     `note_type` narrows to a record kind, or several (e.g. "snippet", or
     ("snippet", "note")), for callers that want prior art rather than everything
     embedded.
@@ -465,7 +537,6 @@ async def semantic_search_notes(
     # Distance ceiling equivalent to the similarity floor. Clamp to the valid
     # cosine-distance range [0, 2] so a threshold of, say, -1 doesn't produce a
     # nonsensical ceiling.
-    max_distance = min(2.0, max(0.0, 1.0 - threshold))
     distance = NoteEmbedding.embedding.cosine_distance(query_vec)
 
     try:
@@ -540,11 +611,10 @@ async def semantic_search_notes(
             fetch = limit * _CHUNK_OVERFETCH * (
                 _SUPERSESSION_OVERFETCH if demote_superseded else 1
             )
-            stmt = (
-                stmt.where(distance <= max_distance)
-                .order_by(distance.asc())
-                .limit(fetch)
-            )
+            # NO threshold predicate — see the note above this function. The
+            # bar is applied after the collapse, where the rejected scores can
+            # still be seen.
+            stmt = stmt.order_by(distance.asc()).limit(fetch)
             rows = list((await session.execute(stmt)).all())
     except Exception:
         logger.warning("Failed to query note embeddings", exc_info=True)
@@ -563,6 +633,11 @@ async def semantic_search_notes(
             continue
         seen.add(int(note.id))
         scored.append((1.0 - float(dist), note))
+    # The best score anything reached, bar or no bar. Recorded BEFORE the
+    # filter because a call that returns nothing is exactly when it matters.
+    if report is not None:
+        report["best_available_score"] = scored[0][0] if scored else None
+    scored = [pair for pair in scored if pair[0] >= threshold]
     if not demote_superseded:
         return scored[:limit]
     return await _apply_supersession_penalty(scored, limit)
@@ -666,6 +741,8 @@ async def upsert_rule_embedding(
     replacement is atomic per rule so a concurrent read sees the old chunk set
     or the new one, never a mixture.
     """
+    from scribe.models.rulebook import Rule  # runtime import: see TYPE_CHECKING above
+
     doc_title, doc_body = rule_document(title, statement, when_to_apply)
     chunks = chunk_document(doc_title, doc_body)
     try:
@@ -688,6 +765,8 @@ async def upsert_rule_embedding(
 
     try:
         async with async_session() as session:
+            if not await _claim_parent_row(session, Rule.id, rule_id, "rule"):
+                return
             await session.execute(
                 delete(RuleEmbedding).where(RuleEmbedding.rule_id == rule_id)
             )
@@ -712,9 +791,16 @@ async def semantic_search_rules(
     limit: int = 5,
     threshold: float = _SIMILARITY_THRESHOLD,
     tier: str | None = None,
+    report: dict | None = None,
 ) -> list[tuple[float, "Rule"]]:
     """Return up to *limit* (score, rule) pairs most relevant to *query*.
 
+    Pass `report` (an empty dict) to learn what the threshold turned away:
+    the function sets `report["best_available_score"]` to the highest score
+    anything reached, or None when the corpus offered nothing at all. It is
+    the only figure that survives a call returning nothing, and therefore the
+    only one a bar can be judged from (#3670).
+
     Scoped by OWNERSHIP — a rule is the caller's if they own its rulebook or
     its project. Deliberately not filtered to what currently BINDS a given
     project: this answers "is there a rule about this", which a person asking
@@ -722,10 +808,17 @@ async def semantic_search_rules(
     is the surfacing question, and it has its own machinery
     (get_applicable_rules) rather than a second, subtly different copy here.
 
-    `tier` narrows to one tier. The write-path hint passes "conditional",
-    because an always-on rule is ALREADY in the session — surfacing it again as
-    a suggestion is pure noise, and noise on a hint that fires on every write
-    is how a hint gets ignored.
+    `tier` narrows to one tier, and NONE is the ordinary case. The write-path
+    and pre-tool hints deliberately pass nothing: an always-on rule is already
+    in the session, but being in a list from turn zero is not the same as being
+    in front of the reader when the action it governs is taken, and filtering
+    on tier made a whole class of rules permanently ineligible for the one
+    mechanism that surfaces a rule AT the moment. Relevance is the threshold's
+    job; see the block above RULEHINT_LIMIT in services/plugin_context.py for
+    the argument and for what the resulting scores are being read against.
+
+    Pass a tier when a caller genuinely wants one class — a listing, an audit,
+    a UI that renders the tiers apart. Not to approximate relevance.
 
     Collapses to best-chunk-per-rule like the note search, so a long rule split
     across chunks competes once rather than crowding the results with itself.
@@ -743,7 +836,6 @@ async def semantic_search_rules(
         logger.debug("Rule search skipped — embedder unavailable")
         return []
 
-    max_distance = min(2.0, max(0.0, 1.0 - threshold))
     distance = RuleEmbedding.embedding.cosine_distance(query_vec)
 
     try:
@@ -757,7 +849,8 @@ async def semantic_search_rules(
                 .outerjoin(Project, Rule.project_id == Project.id)
                 .where(
                     Rule.deleted_at.is_(None),
-                    distance <= max_distance,
+                    # No threshold predicate — see the note above
+                    # semantic_search_notes. Applied below, after the collapse.
                     # topic_id XOR project_id, so exactly one arm can match.
                     or_(
                         Rulebook.owner_user_id == user_id,
@@ -780,7 +873,9 @@ async def semantic_search_rules(
         if rule.id not in best or score > best[rule.id][0]:
             best[rule.id] = (score, rule)
     ranked = sorted(best.values(), key=lambda pair: pair[0], reverse=True)
-    return ranked[:limit]
+    if report is not None:
+        report["best_available_score"] = ranked[0][0] if ranked else None
+    return [pair for pair in ranked if pair[0] >= threshold][:limit]
 
 
 async def backfill_rule_embeddings() -> None:

src/scribe/services/note_usage.py

@@ -30,13 +30,13 @@ from __future__ import annotations
 
 import asyncio
 import logging
-import traceback
 
 from sqlalchemy import case, func, select
 
 from scribe.models import async_session
 from scribe.models.note_usage import PULLED, SURFACED, NoteUsageEvent
 from scribe.models.base import iso
+from scribe.services.background import report_telemetry_failure
 
 logger = logging.getLogger(__name__)
 
@@ -46,37 +46,19 @@ logger = logging.getLogger(__name__)
 # never lands. The done-callback discard keeps the set from growing.
 _pending: set[asyncio.Task] = set()
 
-# Sites that already dropped their once-per-process AppLog row. The readout
-# runs on every snippet list render — without this, a broken table would turn
-# the error log into a firehose that buries the finding it exists to surface.
-_reported: set[str] = set()
-
 
 async def _report_failure(site: str) -> None:
-    """Make a swallowed telemetry failure visible. Called from an except block.
+    """This subsystem's canary, now the shared one.
 
-    WARNING to the process log every time; one AppLog error row per process per
-    site so the admin UI shows the outage without host access. The AppLog write
-    is itself guarded — when the whole database is down it fails too, and that
-    is fine: the WARNING already said so, and a canary must never take down the
-    surface it watches.
+    The per-site dedup, the WARNING and the single AppLog row all moved to
+    `background.report_telemetry_failure` unchanged when `rule_usage` needed
+    the identical behaviour — two hand-kept copies of a thing whose whole job
+    is to be reliable is the wrong number. `retrieval_telemetry` deliberately
+    still has its own: its canary is a different shape (one process-wide flag,
+    no AppLog row), so repointing it would change behaviour rather than
+    consolidate it.
     """
-    logger.warning("note usage telemetry %s failed", site, exc_info=True)
-    if site in _reported:
-        return
-    _reported.add(site)
-    try:
-        from scribe.services.logging import log_error
-
-        await log_error(
-            endpoint="note_usage",
-            error_type=f"note_usage_{site}_failed",
-            error_message=f"note usage telemetry {site} is failing; "
-            "usage counters will read zero until this is fixed",
-            traceback=traceback.format_exc(),
-        )
-    except Exception:
-        logger.debug("note usage canary write failed", exc_info=True)
+    await report_telemetry_failure("note_usage", site)
 
 
 async def _insert_events(rows: list[dict]) -> None:

src/scribe/services/notes.py

@@ -76,6 +76,10 @@ def embed_note(note) -> None:
     exceptions are swallowed because a record that saved must not fail on its
     index refresh. No running loop (unit tests, scripts) is an ordinary case,
     not an error.
+
+    Detaching also means this task races anything that deletes the note out
+    from under it. That is not handled here: `upsert_note_embedding` claims
+    the note's row before touching its vectors, and loses if it can't (#3262).
     """
     try:
         import asyncio

src/scribe/services/planning.py

@@ -60,7 +60,7 @@ async def start_planning(user_id: int, project_id: int, title: str) -> dict:
 
     return {
         "milestone": milestone.to_dict(),
-        **rulebooks_svc.rules_payload(applicable),
+        **rulebooks_svc.rules_payload(applicable, user_id=user_id, source="start_planning"),
         "project_goal": getattr(project, "goal", "") or "",
         "open_task_count": open_count,
     }

src/scribe/services/plugin_context.py

@@ -32,6 +32,7 @@ from scribe.services import snippets as snippets_svc
 from scribe.services.access import label_shared_items, owner_names_for
 from scribe.services.embeddings import semantic_search_notes, semantic_search_rules
 from scribe.services.note_usage import record_surfaced
+from scribe.services.rule_usage import record_rule_surfaced
 from scribe.services.supersession import superseded_ids
 from scribe.services.retrieval_telemetry import record_retrieval
 from scribe.services.settings import get_setting
@@ -85,6 +86,117 @@ WRITEPATH_THRESHOLD_KEY = "kb_writepath_threshold"
 WRITEPATH_DEFAULT_ENABLED = True
 WRITEPATH_DEFAULT_THRESHOLD = 0.68
 
+# The standing-rule arm (milestone 307) gets its own bar — the split #2223 made
+# one surface down, now made for the THIRD corpus. It inherited 0.68 above, and
+# that number was measured against code-vs-note-PROSE. It was never re-derived
+# for code-vs-RULE-TEXT.
+#
+# THE STRUCTURAL ARGUMENT, which is the only kind admissible here (rule 115).
+# Two facts hold on any install, including one with six rules and no telemetry:
+#
+#   1. The eligible corpus is SMALL — every rule an install owns, still only
+#      a few dozen documents against thousands of notes. A top-k over a small
+#      pool always returns something, so "the best match cleared the bar"
+#      drifts from "a good match exists" toward "N things were ranked". A bar
+#      calibrated for best-of-thousands is cleared by best-of-forty as
+#      arithmetic rather than relevance.
+#      This argument WEAKENED when the arms stopped filtering to one tier
+#      (see the note on that below): a larger pool makes clearing the bar
+#      mean more, not less. The threshold was deliberately left where it was
+#      anyway — moving two variables at once would make the resulting
+#      distribution unreadable, and this one errs toward silence on purpose.
+#   2. Rules are short imperative technical English — a far more HOMOGENEOUS
+#      corpus than note prose. #2223 measured the floor for code against prose
+#      at 0.55-0.63 and set 0.68 above it. A more homogeneous corpus has a
+#      HIGHER floor, so 0.68 is not merely inherited, it is below where this
+#      corpus's noise sits.
+#
+# WHY 0.72 AND NOT A NUMBER OFF A HISTOGRAM. The exact offset between prose's
+# floor and rule-text's is not derivable in general — it depends on how an
+# install writes its rules — so the default errs deliberately toward SILENCE
+# rather than toward recall, on an asymmetry that is itself structural: this
+# hint fires on EVERY write. A missed rule is recoverable, because the rule is
+# still in Scribe and the agent can search it. A hint that cries wolf is not:
+# it teaches the reader to skip the whole block, and the surface is lost along
+# with the true positives it would have carried. The arm's own comment already
+# says "noise on a hint that fires on every write is how a hint gets ignored".
+#
+# TUNE IT FROM YOUR OWN INSTANCE, which is now possible: `retrieval_telemetry`
+# reports `rule_usage.pull_through` (milestone 333 step 3). Raise this if rules
+# arrive unread; lower it if rules you needed never arrived. What would RETIRE
+# it: a cross-encoder rerank (#1038), which would make a similarity bar the
+# wrong control entirely.
+RULEHINT_THRESHOLD_KEY = "kb_rulehint_threshold"
+RULEHINT_DEFAULT_THRESHOLD = 0.72
+
+# ONE rule per write, not two — and this is deliberately NOT a knob.
+#
+# With a corpus this small, top-k does as much damage as the threshold: k=2
+# over a few dozen candidates means the second line is almost always the
+# second-best noise, arriving with the same confident framing as the first.
+# Halving k halves that regardless of where the bar sits.
+#
+# It also BOUNDS the blast radius of widening the pool (below): with k=1 a
+# wider corpus can change WHICH rule surfaces and how often one does, but it
+# can never make a single hint longer. The loudness of one hint and the
+# eligibility of a rule are separate controls, and only one of them moved.
+#
+# It stays a constant because it is a decision about how LOUD one hint may be,
+# not a per-install tuning question. The hint already carries prior art, shape
+# signals and staleness; rules are the fourth voice in it, and a fourth voice
+# that speaks twice is where a reader stops reading. Nothing suggests an
+# operator wants this different, and a knob nobody turns is a knob that only
+# adds a way to misconfigure the surface (rule 25 cuts both ways).
+RULEHINT_LIMIT = 1
+
+# WHY THE ARMS NO LONGER FILTER TO ONE TIER (#3702).
+#
+# Both arms used to pass `tier="conditional"`, on the reasoning that an
+# always-on rule is already in the session, so surfacing it again is pure
+# noise. That reasoning conflates two different things:
+#
+#   PRESENT IN CONTEXT  — the rule was delivered at session start.
+#   SALIENT AT THE MOMENT  — the rule is in front of the reader when the
+#                            action it governs is about to be taken.
+#
+# A rule handed over in a list at turn zero is present while a session writes
+# a config value three hundred turns later. It is not surfaced. So the filter
+# did not merely skip a redundant hint — it made a whole class of rules
+# permanently ineligible for the only mechanism that puts a rule in front of
+# an agent AT the moment, and the more important a rule is, the more likely
+# it was in that class.
+#
+# The deeper defect is that the filter was doing the THRESHOLD's job. Whether
+# a rule belongs in this hint is a relevance question, and a similarity bar is
+# the control for relevance. A categorical exclusion standing in for a
+# relevance judgment cannot be tuned, cannot be measured, and cannot be wrong
+# in a way anybody notices.
+#
+# THIS IS A MEASURED CHANGE, NOT A SETTLED ONE. The old comment's fear is
+# real — a hint that fires on every write and says obvious things teaches the
+# reader to skip the block, and the surface is then lost along with its true
+# positives. That fear had simply never been checked. `retrieval_logs` already
+# records top_score, result_count and the query for every call, so the
+# evidence now arrives on its own:
+#
+#   - rules clear the bar often and at high scores  -> the fear was justified,
+#     the filter was a crude proxy for a bar set too low, and the WORK IS THE
+#     BAR. Any reinstated filter should then carry a measured reason.
+#   - rules clear rarely, in a thin band near the bar -> the filter was never
+#     the right instrument and relevance was always sufficient.
+#
+# Only the eligibility moved. The bar and k=1 were both left exactly where
+# they were, so the resulting distribution has one cause.
+
+# How much of a command reaches the embedding (#3476). A shell call is not a
+# file: most are short, and the ones that are not are usually a heredoc or a
+# pasted script whose bulk says nothing about which rule applies. The VERB AND
+# ITS TARGET sit at the front — `curl https://git.fabledsword.com/api/...`,
+# `docker compose up`, `git checkout -b` — and that head is the whole signal.
+# Sending the tail as well would push it out of a 512-token window and let a
+# heredoc's prose decide the match.
+_TOOL_QUERY_CHARS = 400
+
 # Minimum SUBSTANCE (non-whitespace chars) a payload must carry before the
 # semantic arm will run at all — the cheap half of the operator's #89 idea
 # ("a sliding scale between number of characters and semantic threshold").
@@ -351,6 +463,7 @@ async def _reserve_slot_for_reuse(
 
     top_k = cfg["top_k"]
     _t0 = time.perf_counter()
+    _rep: dict = {}
     reuse = await semantic_search_notes(
         user_id, query,
         limit=1,
@@ -359,6 +472,7 @@ async def _reserve_slot_for_reuse(
         exclude_ids=exclude_ids | {int(n.id) for _s, n in kept},
         note_type=_REUSE_KINDS,
         scope="browse",
+        report=_rep,
     )
     # A real semantic query competing for a menu slot — logged like the scored
     # arm it displaces. Before this, the hit it PUSHED OUT was in
@@ -369,6 +483,7 @@ async def _reserve_slot_for_reuse(
         user_id=user_id, source="reuse_slot", query=query,
         threshold=cfg["threshold"], limit=1, project_id=project_id,
         is_task=None, results=reuse,
+        best_available=_rep.get("best_available_score"),
         duration_ms=(time.perf_counter() - _t0) * 1000.0,
     )
     # Verify the kind rather than trusting the query that asked for it, and
@@ -418,6 +533,7 @@ async def build_autoinject_hint(
         return empty
 
     t0 = time.perf_counter()
+    _rep_ai: dict = {}
     hits = await semantic_search_notes(
         user_id, q,
         limit=cfg["top_k"],
@@ -429,11 +545,13 @@ async def build_autoinject_hint(
         # still appear is a collaborator's note inside a shared project — legible
         # only because the line below names its owner.
         scope="browse",
+        report=_rep_ai,
     )
     record_retrieval(
         user_id=user_id, source="auto_inject", query=q,
         threshold=cfg["threshold"], limit=cfg["top_k"],
         project_id=(project_id or None), is_task=None, results=hits,
+        best_available=_rep_ai.get("best_available_score"),
         duration_ms=(time.perf_counter() - t0) * 1000.0,
     )
     if not hits:
@@ -690,10 +808,19 @@ async def get_writepath_config(user_id: int) -> dict:
         threshold = WRITEPATH_DEFAULT_THRESHOLD
     threshold = min(1.0, max(0.0, threshold))
 
+    try:
+        rule_threshold = float(await get_setting(
+            user_id, RULEHINT_THRESHOLD_KEY, str(RULEHINT_DEFAULT_THRESHOLD)))
+    except (TypeError, ValueError):
+        rule_threshold = RULEHINT_DEFAULT_THRESHOLD
+    rule_threshold = min(1.0, max(0.0, rule_threshold))
+
     return {
         **cfg,
         "enabled": enabled_raw.strip().lower() in ("true", "1", "yes", "on"),
         "threshold": threshold,
+        # Its own bar, for a third corpus — see RULEHINT_DEFAULT_THRESHOLD.
+        "rule_threshold": rule_threshold,
     }
 
 
@@ -851,6 +978,7 @@ async def build_write_path_hint(
         # Pulled-and-seen ids stay in the query (as evidence) but never in
         # the menu — the dedup contract holds, the resemblance still lands.
         pulled_seen = seen & set(pulled)
+        _rep_wp: dict = {}
         hits = await semantic_search_notes(
             user_id, query,
             limit=remaining + len(pulled_seen),
@@ -874,12 +1002,40 @@ async def build_write_path_hint(
             # Same reasoning as auto-inject: nobody asked for this, so it takes
             # the browse scope and never surfaces a one-to-one direct share.
             scope="browse",
+            report=_rep_wp,
         )
         resembles = {
             int(note.id): float(score) for score, note in hits
             if int(note.id) in pulled
         }
-        hits = [(s, n) for s, n in hits if int(n.id) not in seen][:remaining]
+        shown = [(s, n) for s, n in hits if int(n.id) not in seen]
+        # WHAT THIS ARM WITHHELD AFTER THE SEARCH ANSWERED, and the reason
+        # `best_available_score` cannot always be reported here (#3739 again,
+        # from the side its fix did not reach).
+        #
+        # This arm is the one note arm that filters TWICE. `exclude_ids` takes
+        # `seen - pulled_seen` into the search, but the pulled-and-seen ids stay
+        # in the query deliberately — `resembles` above needs them — and are
+        # dropped in the line above instead. So the score the search reported is
+        # PRE that drop while the row's `result_count` is POST it, and a record
+        # the session had already been shown could be logged as something the
+        # BAR turned away. Live proof on the first read after #3739 shipped:
+        # write_path's near-miss max was 0.822 while the lowest score it ever
+        # RETURNED was 0.6857 — a "rejection" that beat every acceptance.
+        #
+        # The suppression column cannot rescue it the way it does for the rule
+        # arms: this arm's count would be PARTIAL, covering only the drops made
+        # here and not the ones `exclude_ids` made inside the search, and a
+        # partial number under a name that reads as complete is the substitution
+        # this whole milestone exists to stop.
+        #
+        # So the honest answer is null — "not measured on this call" — whenever
+        # this filter removed anything, because then the bar is not the only
+        # thing that turned something away and the reported score may belong to
+        # a record we withheld ourselves. Calls where nothing was dropped keep
+        # reporting it, which is most of them.
+        withheld_here = len(hits) - len(shown)
+        hits = shown[:remaining]
         record_retrieval(
             user_id=user_id, source="write_path", query=query,
             threshold=cfg["threshold"], limit=remaining,
@@ -887,6 +1043,9 @@ async def build_write_path_hint(
             # recording it as a notes-only retrieval would misdescribe the
             # candidate set the threshold is being tuned against.
             project_id=scope_project, is_task=None, results=hits,
+            best_available=(
+                None if withheld_here else _rep_wp.get("best_available_score")
+            ),
             duration_ms=(time.perf_counter() - t0) * 1000.0,
         )
         if hits:
@@ -1125,10 +1284,18 @@ async def build_write_path_hint(
     rule_ids: list[int] = []
     try:
         already = set(exclude_rule_ids or [])
+        # Timed like the notes arm above. Without this the rule row was the one
+        # source in the whole readout reporting a null p90_duration_ms (#3311)
+        # — a gap that reads as "this surface is somehow not measurable" rather
+        # than "nobody passed the number".
+        rule_t0 = time.perf_counter()
+        _rep_wpr: dict = {}
         hits = await semantic_search_rules(
-            user_id, code or path, limit=2,
-            threshold=cfg["threshold"], tier="conditional",
+            user_id, code or path, limit=RULEHINT_LIMIT,
+            threshold=cfg["rule_threshold"],
+            report=_rep_wpr,
         )
+        rule_ms = (time.perf_counter() - rule_t0) * 1000.0
         fresh = [(score, rule) for score, rule in hits if rule.id not in already]
         for _score, rule in fresh:
             trigger = (rule.when_to_apply or "").strip()
@@ -1139,15 +1306,55 @@ async def build_write_path_hint(
                   "does not apply; it is not in this session's loaded set."
             )
             rule_ids.append(rule.id)
+        # TWO tables, and the split is not arbitrary. retrieval_logs is one
+        # row per CALL, keyed on the score distribution a threshold is tuned
+        # from. rule_usage_events is one row per RULE per event, which is the
+        # grain "was this hint ever acted on" needs and the grain a JSONB
+        # result_ids array cannot be indexed at.
+        #
+        # This comment used to say rule ids had nowhere to go — that
+        # note_usage_events remaps ids on restore, so a rule id there would
+        # return attached to whatever note took that number. That is still
+        # true of the NOTE table, and it is exactly why rule_usage_events is
+        # its own (milestone 333 step 1). The gap it described is closed.
+        #
+        # THE CALL LOG IS UNCONDITIONAL; THE SURFACING LOG IS NOT, and the
+        # asymmetry is the correction #3497 exists to make. Both used to sit
+        # inside an `if fresh:`, which is how this arm came to report
+        # `zero_result_calls: 0` and `cleared_threshold: 133/133` — not a
+        # perfectly tuned surface but one structurally unable to record its
+        # own misses. #3311 read that artifact as a measurement and a whole
+        # milestone was scoped on it. A call that found nothing is the ONLY
+        # evidence a threshold is set too high, and it is the row every note
+        # surface has always written (write_path: 421 zeroes of 613 calls;
+        # auto_inject: 114 of 326). A SURFACING is different in kind: nothing
+        # was shown, so no such event occurred, and its log stays guarded.
+        #
+        # `results=fresh`, not `hits`: the note arms pass their exclusions
+        # INTO semantic_search_notes, so what they log is already
+        # post-exclusion. semantic_search_rules takes no such parameter and
+        # this filter is where the equivalent happens — logging `hits` would
+        # quietly make this row mean something other than every other row in
+        # the same readout.
+        record_retrieval(
+            user_id=user_id, source="write_path_rule", query=code or path,
+            threshold=cfg["rule_threshold"], limit=RULEHINT_LIMIT,
+            project_id=project_id,
+            is_task=None, results=fresh, duration_ms=rule_ms,
+            best_available=_rep_wpr.get("best_available_score"),
+            # What the ranker found and this session had already been told.
+            # Without it a zero row cannot say whether the bar was too high or
+            # the reader was simply ahead of it — and only the first is a
+            # reason to move the threshold.
+            suppressed=len(hits) - len(fresh),
+        )
         if fresh:
-            # retrieval_logs, NOT note_usage_events: that table's ids are
-            # remapped on a backup restore, so a rule id there would return
-            # attached to whatever note took that number. This one is never
-            # restored, and `source` already separates the surfaces.
-            record_retrieval(
-                user_id=user_id, source="write_path_rule", query=code or path,
-                threshold=cfg["threshold"], limit=2, project_id=project_id,
-                is_task=None, results=fresh,
+            # `rule_ids` is `fresh`, i.e. AFTER exclude_rule_ids. A rule the
+            # session already holds was considered and not shown, and counting
+            # it would inflate the denominator with claims the agent never saw
+            # — which reads as a precision problem this arm does not have.
+            record_rule_surfaced(
+                user_id=user_id, rule_ids=rule_ids, source="write_path_rule",
             )
     except Exception:
         logger.debug("write-path rule arm failed", exc_info=True)
@@ -1165,6 +1372,117 @@ async def build_write_path_hint(
     }
 
 
+async def build_tool_rule_hint(
+    user_id: int,
+    tool_name: str,
+    command: str,
+    *,
+    project_id: int = 0,
+    exclude_rule_ids: list[int] | None = None,
+) -> dict:
+    """Standing rules that may apply to the ACTION about to be taken (#3476).
+
+    The sibling of the write-path rule arm, and the surface that was missing.
+    That arm is keyed on `code or path`, so a rule can only be retrieved at the
+    moment of a code WRITE. Every rule about which tool to reach for — don't
+    curl the forge, don't stand up a stack, don't run the suite locally, don't
+    branch — was therefore unreachable at the moment it mattered, and residency
+    in the always-on preload was the only surface it had.
+
+    WHY A MECHANICAL TRIGGER AND NOT AN INSTRUCTION. Note #3089's finding is
+    that a reflex generates no query: you reach for `curl` confidently, with no
+    moment of doubt, so any surface that waits to be asked never fires. Here
+    nothing has to be asked — the tool call IS the query, and the reflex has to
+    become a tool call before it can do anything.
+
+    Deliberately TOOL-AGNOSTIC: takes a name and a string. The hook decides
+    which tools it watches, so widening the matcher is a `hooks.json` edit with
+    no change here.
+
+    CONDITIONAL ONLY, exactly as the write-path arm — an always-on rule is
+    already resident and repeating it is noise. That filter is also the
+    transition this arm exists to enable: re-tier a rule to `conditional` and
+    it starts arriving here instead of in every session's preamble.
+
+    Fails open and returns an empty context on any error: a recall aid may
+    never break the operator's action.
+    """
+    out: dict = {"context": "", "rule_ids": []}
+    command = (command or "").strip()
+    if not command:
+        return out
+
+    try:
+        cfg = await get_writepath_config(user_id)
+        if not cfg.get("enabled"):
+            return out
+
+        # The command text is the query. A long heredoc or a pasted script
+        # would otherwise push the meaningful head of the command out of the
+        # embedding window, so it is bounded — the verb and its target sit at
+        # the front, which is the part a rule is about.
+        query = command[:_TOOL_QUERY_CHARS]
+
+        t0 = time.perf_counter()
+        _rep_ptr: dict = {}
+        hits = await semantic_search_rules(
+            user_id, query, limit=RULEHINT_LIMIT,
+            threshold=cfg["rule_threshold"],
+            report=_rep_ptr,
+        )
+        duration_ms = (time.perf_counter() - t0) * 1000.0
+
+        already = set(exclude_rule_ids or [])
+        fresh = [(score, rule) for score, rule in hits if rule.id not in already]
+
+        # Logged BEFORE the early return, for the reason spelled out at length
+        # on the write-path arm above: a call that found nothing is the only
+        # evidence a threshold is too high, and an arm that logs only the calls
+        # it liked reports a flawless clear-rate however badly it is tuned.
+        # This arm shipped with the same defect inherited from its sibling, and
+        # it mattered more here — a surface with no rows at all cannot be told
+        # apart from a hook that never fired, which is precisely the silent
+        # failure the arm was built to stop.
+        record_retrieval(
+            user_id=user_id, source="pre_tool_rule", query=query,
+            threshold=cfg["rule_threshold"], limit=RULEHINT_LIMIT,
+            project_id=project_id,
+            is_task=None, results=fresh, duration_ms=duration_ms,
+            best_available=_rep_ptr.get("best_available_score"),
+            # See the sibling arm. It matters more here: this arm fires on every
+            # Bash call, so a long session excludes its way to an all-zero row
+            # and the threshold looks wrong when nothing about it is.
+            suppressed=len(hits) - len(fresh),
+        )
+        if not fresh:
+            return out
+
+        lines: list[str] = []
+        rule_ids: list[int] = []
+        for _score, rule in fresh:
+            trigger = (rule.when_to_apply or "").strip()
+            lines.append(
+                f"Standing rule that may apply to this {tool_name} call — "
+                f"“{rule.title}”"
+                + (f" ({trigger})" if trigger else "")
+                + f". Read it with get_rule({rule.id}) before deciding it "
+                  "does not apply; it is not in this session's loaded set."
+            )
+            rule_ids.append(rule.id)
+
+        # RANKED, not ambient: this arm chose what it showed, so a pull can
+        # settle whether the choice was any good. `rule_usage.RANKED_SOURCES`
+        # carries the same name.
+        record_rule_surfaced(
+            user_id=user_id, rule_ids=rule_ids, source="pre_tool_rule",
+        )
+        out["context"] = "\n".join(lines)
+        out["rule_ids"] = rule_ids
+    except Exception:
+        logger.debug("pre-tool rule arm failed", exc_info=True)
+    return out
+
+
 def _derive_line(path: str, derive: list[dict]) -> str:
     """The ledger's word on the names being written (#2900): a duplicate
     family to derive, or a canon to reuse — said at the write."""
@@ -1290,6 +1608,24 @@ async def build_session_context(
     # exclusion (milestone 297) takes a rulebook out of this block, and is
     # named below so the departure is visible rather than silent.
     rules = await rulebooks_svc.list_always_on_rules(user_id, project_id=project_id)
+    # AMBIENT source, and the one that matters most: this is the preload — the
+    # block every session opens with, chosen by nobody, paid for every turn.
+    #
+    # It emitted nothing until 2026-09-03, which made the resident set's cost
+    # certain and its usefulness unfalsifiable at the same time (#3473). Note
+    # #3089 is the argument this measurement finally lets someone test: that a
+    # rule arriving with thirty others, none of them relevant, is read as
+    # preamble rather than as a claim — so presence is not surfacing, and a
+    # tier-1 set can grow without anybody noticing it stopped working.
+    #
+    # Recorded even when the hook truncates the block below: the rules WERE
+    # delivered, and counting only the untruncated ones would quietly shrink
+    # the denominator exactly where the set is too big to read.
+    record_rule_surfaced(
+        user_id=user_id,
+        rule_ids=[r.id for r in rules],
+        source="session_start",
+    )
     excluded = (
         await rulebooks_svc.excluded_always_on_rulebooks(user_id, project_id)
         if project_id else []

src/scribe/services/retrieval_telemetry.py

@@ -27,6 +27,10 @@ from scribe.models import async_session
 from scribe.models.base import iso
 from scribe.models.note import Note
 from scribe.models.note_usage import PULLED, SURFACED, NoteUsageEvent
+from scribe.models.rule_usage import PULLED as RULE_PULLED
+from scribe.models.rule_usage import SURFACED as RULE_SURFACED
+from scribe.models.rule_usage import RuleUsageEvent
+from scribe.services.rule_usage import is_ambient
 from scribe.models.retrieval_log import RetrievalLog
 
 logger = logging.getLogger(__name__)
@@ -51,12 +55,26 @@ def _build_payload(
     is_task: bool | None,
     results: list[tuple[float, Note]],
     duration_ms: float | None,
+    suppressed: int | None = None,
+    best_available: float | None = None,
 ) -> dict:
     """Reduce a retrieval call to a flat, JSON-safe RetrievalLog payload.
 
     Pure and synchronous (no DB, no event loop) so it is unit-testable and safe
     to run inline before scheduling the write. `results` is the
     `(score, Note)` list from semantic_search_notes, already highest-first.
+
+    `suppressed` is how many scored hits the caller dropped because the session
+    had already been shown them, and it stays None for callers that cannot
+    know. See the column's comment: None means "not measured here", which is a
+    different fact from 0 and must never render as one.
+
+    `best_available` is the highest score the ranker reached BEFORE the
+    threshold, and it carries the same null discipline for a sharper reason: it
+    is the only field that still says something on a call that returned
+    nothing, so a 0.0 standing in for "not measured" would read as "the corpus
+    held nothing remotely relevant" — a claim about the corpus invented out of
+    a caller's silence.
     """
     items = [
         {"id": int(note.id), "score": round(float(score), 5), "rank": rank}
@@ -72,8 +90,12 @@ def _build_payload(
         "project_id": project_id,
         "is_task": is_task,
         "result_count": len(items),
+        "suppressed_count": (None if suppressed is None else int(suppressed)),
         "top_score": (scores[0] if scores else None),
         "min_score": (scores[-1] if scores else None),
+        "best_available_score": (
+            None if best_available is None else round(float(best_available), 5)
+        ),
         "result_ids": items,
         "duration_ms": (round(duration_ms, 2) if duration_ms is not None else None),
     }
@@ -111,6 +133,8 @@ def record_retrieval(
     is_task: bool | None,
     results: list[tuple[float, Any]],
     duration_ms: float | None = None,
+    suppressed: int | None = None,
+    best_available: float | None = None,
 ) -> None:
     """Fire-and-forget: record one retrieval call.
 
@@ -136,6 +160,8 @@ def record_retrieval(
             is_task=is_task,
             results=results,
             duration_ms=duration_ms,
+            suppressed=suppressed,
+            best_available=best_available,
         )
     except Exception:
         logger.debug("retrieval telemetry payload build failed", exc_info=True)
@@ -162,36 +188,145 @@ def record_retrieval(
 
 def _bucket(rows: list) -> dict:
     """A score readout a human can act on, from one aggregate row."""
-    calls, zero, cleared, p10, p50, p90, lo, hi, avg_n, dur = rows
+    (calls, zero, p10, p50, p90, lo, hi, avg_n, dur,
+     measured, supp_calls, supp_zero,
+     miss_calls, miss_p50, miss_p90, miss_max) = rows
     return {
         "calls": int(calls or 0),
         # A call that returned nothing is not a low-scoring call — it is a
         # different failure (nothing indexed, filter too narrow), and averaging
         # it into the score distribution would hide both.
         "zero_result_calls": int(zero or 0),
-        # How often the best hit actually cleared the threshold in force for
-        # that call. THE precision-adjacent number: a surface that clears its
-        # bar on almost every call is either well-tuned or too loose, and the
-        # score spread below says which.
-        "cleared_threshold": int(cleared or 0),
+        # `cleared_threshold` USED TO LIVE HERE and it was a tautology (#3670).
+        # The search applies the bar before returning, so every returned result
+        # cleared it by construction and a call with nothing has no score to
+        # compare — the condition was true exactly when `result_count > 0`.
+        # `zero_result_calls + cleared_threshold == calls` held on all nineteen
+        # readings ever taken. It was `calls - zero_result_calls` wearing a name
+        # that promised a second opinion, and the docstring built a reading
+        # procedure on it that asked the reader to compare a number with itself.
+        # Its replacement is `near_misses` below, which the bar cannot fix by
+        # construction because it is measured on the calls the bar REJECTED.
+        # Of the zeros above, which were the RANKER declining and which were
+        # the reader having seen it already? `zero_result_calls` cannot say,
+        # and only the first kind is evidence about the threshold.
+        #
+        # None — not a zeroed dict — when no row in the window reported it. A
+        # surface that filters inside the search genuinely does not know, and
+        # rendering that as `{"calls": 0}` would state a measurement nobody
+        # made. That substitution is the whole of #3311.
+        "suppression": (
+            None if not int(measured or 0) else {
+                "measured_calls": int(measured or 0),
+                "calls_with_suppression": int(supp_calls or 0),
+                # Subtract from zero_result_calls for the true ranker declines.
+                "zero_because_already_shown": int(supp_zero or 0),
+            }
+        ),
         "top_score": {
             "p10": _round(p10), "p50": _round(p50), "p90": _round(p90),
             "min": _round(lo), "max": _round(hi),
         },
+        # WHAT THE BAR TURNED AWAY, and the only figure here a threshold can
+        # actually be tuned from. Measured over the calls that returned
+        # NOTHING, on the best score the ranker reached before the filter.
+        #
+        # Read `p90` against the threshold in force. A bar at 0.72 rejecting a
+        # stream of 0.71s is set too high by a hair and the surface is losing
+        # hits it should have had; the same bar rejecting 0.30s is doing its
+        # job and the corpus simply had nothing. Both render as a zero-result
+        # call, and nothing else in this readout separates them.
+        #
+        # None — not a zeroed block — when no declining call in the window
+        # measured it. Old rows predate the column, and a 0.0 would assert that
+        # the corpus held nothing relevant, which is a claim about the corpus
+        # invented out of a caller's silence.
+        "near_misses": (
+            None if not int(miss_calls or 0) else {
+                "measured_calls": int(miss_calls or 0),
+                "p50": _round(miss_p50),
+                "p90": _round(miss_p90),
+                "max": _round(miss_max),
+            }
+        ),
         "avg_result_count": _round(avg_n),
         "p90_duration_ms": _round(dur, 1),
     }
 
 
+# The aggregate row Postgres would have returned for a source with no rows in
+# the window: nothing counted, nothing scored. Positional, matching the SELECT
+# `_bucket` unpacks — calls, zero, p10, p50, p90, min, max, avg_n,
+# dur, measured, supp_calls, supp_zero, miss_calls, miss_p50, miss_p90,
+# miss_max. The counts are 0 because zero calls is a real observation;
+# everything else is None because a distribution nobody sampled has no value,
+# and rendering it as 0.0 would state one.
+_NO_ROWS_IN_WINDOW = [0, 0, None, None, None, None, None, None, None,
+                      0, 0, 0, 0, None, None, None]
+
+
 def _round(v, places: int = 4):
     return None if v is None else round(float(v), places)
 
 
+async def _complete_from(session, model, user_id) -> dict[str, Any]:
+    """When each source in `model` started being recorded, and the instant the
+    WHOLE table is complete from. Returns {source: earliest_row, "*": latest}.
+
+    THE GRAIN IS THE SOURCE, and that is the whole point. `retrieval_logs` has
+    rows going back months, so a table-level "earliest row" says months and
+    tells a reader their window is fully covered — while a source added last
+    week has a week of rows and a counter that silently means something else.
+    Per-source is the only grain at which partial coverage is visible.
+
+    THE AGGREGATE USES THE LATEST, NOT THE EARLIEST. A number that sums several
+    sources is complete only once EVERY contributor was recording, so "*" is a
+    max over the sources, not a min. Taking the min here would reproduce the
+    exact reading this exists to prevent: the oldest source vouching for the
+    youngest.
+
+    All-time, deliberately unfiltered by the window — a query bounded by
+    `since` can only ever report something at or after `since`, which answers
+    nothing.
+    """
+    rows = (
+        await session.execute(
+            select(model.source, func.min(model.created_at))
+            .where(model.user_id == user_id)
+            .group_by(model.source)
+        )
+    ).all()
+    out: dict[str, Any] = {src: ts for src, ts in rows if ts is not None}
+    stamps = list(out.values())
+    out["*"] = max(stamps) if stamps else None
+    return out
+
+
+def _coverage(complete_from, since) -> dict:
+    """The two keys every counter block carries, from one timestamp.
+
+    `covers_window` is None — never False — when nothing was ever recorded.
+    "No rows at all" is not "partial coverage", it is no measurement, and the
+    null convention #3497 established for `suppression` holds here for the
+    same reason: absent must not read as a verdict.
+    """
+    return {
+        # iso() already returns None for an unset value (#2845) — the guard
+        # belongs on covers_window, which is a verdict, not a serialisation.
+        "complete_from": iso(complete_from),
+        "covers_window": (
+            None if complete_from is None else complete_from <= since
+        ),
+    }
+
+
 async def retrieval_summary(user_id: int | None, *, days: int = 30) -> dict:
     """What the retrieval telemetry says, per surface, over a window.
 
-    Two aggregates side by side, each read from the table built for it — NOT a
-    join. `NoteUsageEvent`'s own docstring is explicit that the two are
+    Three aggregates side by side, each read from the table built for it — NOT
+    a join. `usage` is notes, `rule_usage` is rules, and they stay apart
+    because a few dozen eligible rules blended into thousands of notes is the
+    note ratio with noise on it (milestone 333). `NoteUsageEvent`'s own docstring is explicit that the two are
     complements ("RetrievalLog tunes the threshold, this tunes the corpus") and
     that RetrievalLog's JSONB `result_ids` "can't be indexed at" the per-note
     grain. So the score distribution comes from `retrieval_logs` on its indexed
@@ -199,6 +334,12 @@ async def retrieval_summary(user_id: int | None, *, days: int = 30) -> dict:
     it was built for. Reading each from its own table is both cheaper and more
     honest than correlating them through JSONB.
 
+    `usage["by_source"]` is the one join, and it stays INSIDE
+    `note_usage_events` — surfaced rows against pulled rows on note_id. That
+    answers "of the notes this surface chose, how many were opened", which the
+    top-level ratio averages away. It does not cross into `retrieval_logs`, so
+    the sentence above still holds.
+
     Scoped to one user's own telemetry. There is no sharing model for a
     retrieval log — it records what THIS user's agent asked for, including the
     query text — so an owner filter is the whole access rule here rather than a
@@ -214,23 +355,77 @@ async def retrieval_summary(user_id: int | None, *, days: int = 30) -> dict:
         "since": iso(since),
         "sources": {},
         "usage": {},
+        "rule_usage": {},
         "read_failed": False,
     }
 
-    cleared = case(
-        (
-            (RetrievalLog.threshold.isnot(None))
-            & (RetrievalLog.top_score.isnot(None))
-            & (RetrievalLog.top_score >= RetrievalLog.threshold),
-            1,
-        ),
+    zero = case((RetrievalLog.result_count == 0, 1), else_=0)
+    # THE NEAR-MISS POPULATION: calls that returned nothing BECAUSE THE BAR
+    # TURNED SOMETHING AWAY, and recorded what it was. Three conditions, and
+    # the third was missing for one deploy (#3739).
+    #
+    # Zero-result only: on a call that returned something,
+    # `best_available_score` equals `top_score` and adds nothing.
+    #
+    # Non-null only: rows written before #3670 genuinely do not know, and must
+    # not read as scoreless declines.
+    #
+    # AND NOT A REPEAT. A zero-result call is two unrelated events — the ranker
+    # found nothing above the bar, or it found only what this session had
+    # already been shown — and just the first says anything about the bar. That
+    # is the whole of #3497, and #3670 reintroduced the conflation one level up:
+    # the rule arms filter exclusions in PYTHON, after the search, so a rule
+    # that cleared the bar and was dropped as a repeat still reported a high
+    # `best_available_score` on a zero-result row. Live proof, first read after
+    # deploy: pre_tool_rule's near-miss max was 0.7457 while the lowest score it
+    # ever RETURNED was 0.7204 — a "rejection" that outscored acceptances.
+    #
+    # The NULL arm is principled, not permissive: `suppressed_count IS NULL`
+    # means the caller passed its exclusions INTO the search, which is exactly
+    # the case where the reported score is already post-exclusion and cannot be
+    # contaminated. Note arms stay measured; rule arms get cleaned.
+    #
+    # Deliberately conservative: a call carrying both a repeat and a lower
+    # genuine miss is dropped whole, losing that point. It undercounts; it
+    # cannot corrupt — the right way round for a number read against a bar.
+    #
+    # This also makes `near_misses.max < threshold` true BY CONSTRUCTION. An
+    # above-bar candidate that was not excluded would have been returned, so
+    # its call is not in this population at all.
+    declined = (
+        (RetrievalLog.result_count == 0)
+        & (RetrievalLog.best_available_score.isnot(None))
+        & (
+            RetrievalLog.suppressed_count.is_(None)
+            | (RetrievalLog.suppressed_count == 0)
+        )
+    )
+    miss = case((declined, 1), else_=0)
+    # `best_available_score` only for those rows; NULL elsewhere, and
+    # percentile_cont ignores NULLs, so the distribution is over the declines
+    # alone without a second pass over the table.
+    miss_score = case((declined, RetrievalLog.best_available_score), else_=None)
+    # Three sums rather than one, because "not measured" and "measured as zero"
+    # are different answers and a single counter cannot hold both.
+    measured = case((RetrievalLog.suppressed_count.isnot(None), 1), else_=0)
+    supp_calls = case((RetrievalLog.suppressed_count > 0, 1), else_=0)
+    supp_zero = case(
+        ((RetrievalLog.result_count == 0) & (RetrievalLog.suppressed_count > 0), 1),
         else_=0,
     )
-    zero = case((RetrievalLog.result_count == 0, 1), else_=0)
 
     def pct(p: float):
         return func.percentile_cont(p).within_group(RetrievalLog.top_score.asc())
 
+    # Assigned inside the try below; named here so the readout can tell
+    # "this query failed" from "this window has no rows" (#2663).
+    by_source_rows = None
+    rule_rows = None
+    distinct_rules_surfaced = distinct_rules_pulled = 0
+    # None means the coverage read did not happen — distinct from a table with
+    # no rows, which is {"*": None}. Same reason `read_failed` exists.
+    note_complete = rule_complete = None
+
     try:
         async with async_session() as session:
             rows = (
@@ -239,7 +434,6 @@ async def retrieval_summary(user_id: int | None, *, days: int = 30) -> dict:
                         RetrievalLog.source,
                         func.count().label("calls"),
                         func.sum(zero).label("zero"),
-                        func.sum(cleared).label("cleared"),
                         pct(0.1), pct(0.5), pct(0.9),
                         func.min(RetrievalLog.top_score),
                         func.max(RetrievalLog.top_score),
@@ -247,6 +441,13 @@ async def retrieval_summary(user_id: int | None, *, days: int = 30) -> dict:
                         func.percentile_cont(0.9).within_group(
                             RetrievalLog.duration_ms.asc()
                         ),
+                        func.sum(measured).label("measured"),
+                        func.sum(supp_calls).label("supp_calls"),
+                        func.sum(supp_zero).label("supp_zero"),
+                        func.sum(miss).label("miss_calls"),
+                        func.percentile_cont(0.5).within_group(miss_score.asc()),
+                        func.percentile_cont(0.9).within_group(miss_score.asc()),
+                        func.max(miss_score),
                     )
                     .where(
                         RetrievalLog.created_at >= since,
@@ -255,8 +456,34 @@ async def retrieval_summary(user_id: int | None, *, days: int = 30) -> dict:
                     .group_by(RetrievalLog.source)
                 )
             ).all()
+            log_complete = await _complete_from(session, RetrievalLog, user_id)
             for row in rows:
-                out["sources"][row[0]] = _bucket(list(row[1:]))
+                source = row[0]
+                bucket = _bucket(list(row[1:]))
+                # Per SOURCE, not per table: retrieval_logs goes back months
+                # while any individual arm may be days old, and the table's
+                # age would vouch for an arm that has barely started.
+                bucket.update(_coverage(log_complete.get(source), since))
+                out["sources"][source] = bucket
+
+            # A source with rows in the table but NONE in this window would
+            # otherwise be absent from the readout — and absent is exactly how
+            # a source that never existed renders, so a surface that WAS
+            # recording and went silent is unreadable (#3720). That is #2663
+            # one level up: the failure that looks like the correct answer.
+            #
+            # Zero here is a real measurement, not a manufactured one. The
+            # all-time query proves the source was recording, and it made no
+            # calls across a window it fully covers — which is why no
+            # `covers_window` special case is needed: a source whose first row
+            # fell after `since` would have that row IN the window and already
+            # hold a bucket, so anything reaching here began before it.
+            for src, first_row in log_complete.items():
+                if src == "*" or first_row is None or src in out["sources"]:
+                    continue
+                quiet = _bucket(list(_NO_ROWS_IN_WINDOW))
+                quiet.update(_coverage(first_row, since))
+                out["sources"][src] = quiet
 
             # The corpus side, at its own grain. `ambient` mirrors
             # note_usage.usage_for_notes: an ambient surfacing was not a scored
@@ -283,6 +510,7 @@ async def retrieval_summary(user_id: int | None, *, days: int = 30) -> dict:
                     .group_by(NoteUsageEvent.event, NoteUsageEvent.source)
                 )
             ).all()
+            note_complete = await _complete_from(session, NoteUsageEvent, user_id)
 
             # Distinct-note counts need their OWN queries, and this is not
             # fussiness: count(distinct note_id) per (event, source) group
@@ -310,6 +538,142 @@ async def retrieval_summary(user_id: int | None, *, days: int = 30) -> dict:
                     )
                 )
             ).scalar_one()
+
+            # Per-source pull-through, at the NOTE grain (#3311).
+            #
+            # The `urows` query above already groups by source and the loop
+            # below then throws the source away, so until now this readout
+            # could say what the corpus's overall pull-through was and nothing
+            # about WHICH surface earned it. The data was always here; only
+            # the aggregation discarded it.
+            #
+            # It cannot be had by grouping the PULLED rows by source: a pull
+            # records the door it came through (`mcp_get_note`), not the
+            # surface that put the record in front of the agent. Correlating
+            # those within a session is what #2085 ruled out — there is no
+            # session identity server-side and inventing one would mean
+            # threading a client-supplied token through every read path. The
+            # note grain answers the question without one: of the distinct
+            # notes surface X chose, how many did an agent open in this window?
+            #
+            # Guarded separately from the reads above, on #2663's actual
+            # lesson. That outage was a NOVEL SQL SHAPE the database rejected
+            # inside a broad except. This join is the novel shape here, and a
+            # failure in it must not take down two readouts that already work.
+            try:
+                pulled_ids = (
+                    select(NoteUsageEvent.note_id)
+                    .where(
+                        NoteUsageEvent.created_at >= since,
+                        NoteUsageEvent.user_id == user_id,
+                        NoteUsageEvent.event == PULLED,
+                        # autoescape because `_` is a LIKE wildcard: a bare
+                        # like("mcp_%") also matches "mcpX…". The Python half
+                        # of this readout uses str.startswith and has no such
+                        # hazard; this is the SQL half's version of it.
+                        NoteUsageEvent.source.startswith("mcp_", autoescape=True),
+                    )
+                    .distinct()
+                    .subquery()
+                )
+                surfaced_pairs = (
+                    select(NoteUsageEvent.source, NoteUsageEvent.note_id)
+                    .where(
+                        NoteUsageEvent.created_at >= since,
+                        NoteUsageEvent.user_id == user_id,
+                        NoteUsageEvent.event == SURFACED,
+                    )
+                    .distinct()
+                    .subquery()
+                )
+                # DISTINCT on (source, note_id) FIRST, which is what lets the
+                # outer aggregate be a plain count(): the pairs are already
+                # unique, so the left join cannot multiply them and no
+                # count(DISTINCT) is needed to undo damage that never happens.
+                by_source_rows = (
+                    await session.execute(
+                        select(
+                            surfaced_pairs.c.source,
+                            func.count().label("notes_surfaced"),
+                            func.count(pulled_ids.c.note_id).label("notes_pulled"),
+                        )
+                        .select_from(
+                            surfaced_pairs.outerjoin(
+                                pulled_ids,
+                                pulled_ids.c.note_id == surfaced_pairs.c.note_id,
+                            )
+                        )
+                        .group_by(surfaced_pairs.c.source)
+                    )
+                ).all()
+            except Exception:
+                logger.warning("per-source pull-through read failed", exc_info=True)
+                by_source_rows = None
+
+            # Rules, at their own grain and in their own block (milestone 333).
+            #
+            # Guarded separately from the reads above for the reason `by_source`
+            # is: this table is NEW, and an instance running upgraded code
+            # against un-migrated schema would otherwise take down two readouts
+            # that work perfectly in order to report a third that cannot.
+            #
+            # The queries themselves are the note block's shapes, not novel
+            # ones — a group-by on two indexed columns and two count(distinct).
+            # The distinct counts need their own queries for the same reason
+            # the note ones do: count(distinct rule_id) per group cannot be
+            # summed across groups without double-counting a rule two sources
+            # both touched.
+            try:
+                rule_rows = (
+                    await session.execute(
+                        select(
+                            RuleUsageEvent.event,
+                            RuleUsageEvent.source,
+                            func.count().label("n"),
+                        )
+                        .where(
+                            RuleUsageEvent.created_at >= since,
+                            RuleUsageEvent.user_id == user_id,
+                        )
+                        .group_by(RuleUsageEvent.event, RuleUsageEvent.source)
+                    )
+                ).all()
+                rule_complete = await _complete_from(
+                    session, RuleUsageEvent, user_id,
+                )
+                # The rows carry `source`, so the ranked/ambient split is done
+                # below rather than in SQL — the bulk surfaces started emitting
+                # on 2026-09-03 (#3473), so there IS an ambient class now.
+                #
+                # `distinct_rules_surfaced` deliberately counts BOTH classes. It
+                # answers "how many distinct rules did this install put in front
+                # of an agent at all", which is the denominator for dead weight
+                # — and a rule delivered by the preload a hundred times and
+                # never opened is the most important case that question has.
+                distinct_rules_surfaced = (
+                    await session.execute(
+                        select(func.count(func.distinct(RuleUsageEvent.rule_id)))
+                        .where(
+                            RuleUsageEvent.created_at >= since,
+                            RuleUsageEvent.user_id == user_id,
+                            RuleUsageEvent.event == RULE_SURFACED,
+                        )
+                    )
+                ).scalar_one()
+                distinct_rules_pulled = (
+                    await session.execute(
+                        select(func.count(func.distinct(RuleUsageEvent.rule_id)))
+                        .where(
+                            RuleUsageEvent.created_at >= since,
+                            RuleUsageEvent.user_id == user_id,
+                            RuleUsageEvent.event == RULE_PULLED,
+                        )
+                    )
+                ).scalar_one()
+            except Exception:
+                logger.warning("rule usage read failed", exc_info=True)
+                rule_rows = None
+                distinct_rules_surfaced = distinct_rules_pulled = 0
     except Exception:
         logger.warning("retrieval summary read failed", exc_info=True)
         out["read_failed"] = True
@@ -350,5 +714,124 @@ async def retrieval_summary(user_id: int | None, *, days: int = 30) -> dict:
         round(usage["pulled_by_agent"] / usage["surfaced"], 4)
         if usage["surfaced"] else None
     )
+
+    # The same question, per surface — which is the one the top-level ratio
+    # cannot answer. A corpus average of 0.05 is compatible with one surface
+    # earning its noise and another producing none, and tuning a threshold
+    # needs to know which.
+    #
+    # UPPER BOUND, and say so where it will be read: a pull records the door,
+    # not the surface that led to it, so a note surfaced by two surfaces and
+    # opened once counts as pulled for both. Attribution would need the session
+    # identity #2085 declined to invent. The bound is still decisive in the
+    # direction that matters — a surface reading near zero here is not being
+    # flattered by the double-count.
+    if by_source_rows is None:
+        usage["by_source"] = {}
+        # Distinct from an empty window, for the same reason `read_failed` is.
+        usage["by_source_failed"] = True
+    else:
+        by_source: dict[str, dict] = {}
+        for source, n_surfaced, n_pulled in by_source_rows:
+            n_surfaced, n_pulled = int(n_surfaced or 0), int(n_pulled or 0)
+            ambient = source in AMBIENT_SOURCES
+            by_source[source] = {
+                "notes_surfaced": n_surfaced,
+                "notes_pulled": n_pulled,
+                # None rather than a number on an ambient surface: nothing
+                # CHOSE those records, so "surfaced often, opened never" is not
+                # a judgment about them. The counts stay visible; the ratio
+                # that would be misread does not.
+                "pull_through": (
+                    None if ambient or not n_surfaced
+                    else round(n_pulled / n_surfaced, 4)
+                ),
+                "ambient": ambient,
+            }
+        usage["by_source"] = by_source
+
+    # The SECTION's coverage, from the latest source to start recording — a
+    # figure that sums several sources is complete only once every one of them
+    # was being written. `_complete_from` computes that as "*".
+    usage.update(_coverage((note_complete or {}).get("*"), since))
     out["usage"] = usage
+
+    # ── Rules, deliberately a SEPARATE block ────────────────────────────
+    #
+    # Not folded into `usage`, for two reasons and the second is the one that
+    # bites. The corpora differ by orders of magnitude — a few dozen eligible
+    # rules against thousands of notes — so one blended ratio would be the note
+    # ratio with a little noise on it, and the rule arm's own behaviour would
+    # be undetectable inside it. And `usage` is what existing callers already
+    # read: silently changing what it counts would move a number people have
+    # been comparing across windows, without telling them it now measures
+    # something else.
+    #
+    # `ambient` now carries the bulk deliveries — the SessionStart preload,
+    # `list_always_on_rules`, and every `rules_payload` surface (#3473). Before
+    # they emitted, this block had no ambient key and said the absence was a
+    # fact about the data. It was, and it was also the thing that made the
+    # always-on set impossible to judge: the largest rule surface in the
+    # product was the one surface its own scoreboard could not see.
+    #
+    # READ THE TWO SEPARATELY, ALWAYS. `surfaced` is a claim a ranker made and
+    # a pull can settle. `ambient` is a delivery nobody chose, so a high count
+    # says the set is large and resident, never that it is useful.
+    rule_usage = {
+        "surfaced": 0, "ambient": 0,
+        "pulled": 0, "pulled_by_agent": 0, "pulled_by_human": 0,
+        "distinct_rules_surfaced": int(distinct_rules_surfaced or 0),
+        "distinct_rules_pulled": int(distinct_rules_pulled or 0),
+    }
+    if rule_rows is None:
+        # The FLAG is added, the shape is kept — matching `by_source_failed`
+        # one block up. A caller that renders this must not have to choose
+        # between crashing on a missing key and quietly showing zeros it has no
+        # right to: the keys let it render, and the flag tells it the zeros are
+        # "we could not find out" rather than "nothing happened" (#2663).
+        rule_usage["rule_usage_failed"] = True
+    else:
+        for event, source, n in rule_rows:
+            n = int(n)
+            if event == RULE_SURFACED:
+                # One definition of ranked-vs-ambient, imported rather than
+                # restated — the per-rule badge readout reads the same
+                # predicate, and two spellings of "what counts as surfaced" is
+                # precisely the uneven wiring #3246 found across this system.
+                if is_ambient(source):
+                    rule_usage["ambient"] += n
+                else:
+                    rule_usage["surfaced"] += n
+            elif event == RULE_PULLED:
+                rule_usage["pulled"] += n
+                # Same split, and it carries MORE weight here than for notes.
+                # The arm's whole claim is "this rule may apply to what you are
+                # writing", and only an agent opening it says the claim landed.
+                # A person browsing the rule list says nothing about the hint.
+                if source.startswith("mcp_"):
+                    rule_usage["pulled_by_agent"] += n
+                else:
+                    rule_usage["pulled_by_human"] += n
+
+    # None, not 0.0, when nothing was surfaced — matching the note block. A
+    # ratio of zero asserts "we showed rules and none were opened"; with an
+    # empty numerator AND denominator that is a claim the data does not
+    # support, and it is the reading that would make a brand-new install look
+    # like a broken one.
+    #
+    # RANKED SURFACINGS ONLY in the denominator, and this is the load-bearing
+    # line of the whole change. Pull-through asks "was that hint any use", and
+    # only a surface that CHOSE what it showed can be judged by it. Folding the
+    # preload in would divide the same pulls by a number that grows with every
+    # session and every rule added to the resident set — so enlarging the
+    # always-on set would DEPRESS the arm's measured precision, and trimming it
+    # would flatter it, neither for any reason to do with the arm. The ambient
+    # count sits beside it, unaveraged, and is read as size rather than skill.
+    rule_usage["pull_through"] = (
+        round(rule_usage["pulled_by_agent"] / rule_usage["surfaced"], 4)
+        if rule_usage["surfaced"] else None
+    )
+    rule_usage.update(_coverage((rule_complete or {}).get("*"), since))
+    out["rule_usage"] = rule_usage
+
     return out

src/scribe/services/rule_usage.py

@@ -0,0 +1,295 @@
+"""Rule usage telemetry — did a surfaced rule ever get read?
+
+The sibling of `note_usage`, for the one retrieval surface in Scribe that
+could not be measured at all.
+
+Two event streams, deliberately independent:
+
+  - SURFACED: the write-path standing-rule arm put this rule in front of the
+    agent, unbidden, during a write.
+  - PULLED: someone then opened it in full (`get_rule`, or the REST detail
+    route).
+
+WHY THIS ARM AND NOT ANOTHER. Every other surface declines most of the time —
+`write_path` returns nothing on 78% of calls, `reuse_slot` on 79%, auto-inject
+on 39%. The rule arm APPEARED never to have returned nothing (#3311), and this
+docstring used to put that forward as the puzzle worth measuring: "either a
+perfectly tuned surface or a bar it cannot fail to clear".
+
+It was neither, and the correction belongs here rather than being quietly
+deleted. The arm wrote its `retrieval_logs` row only on calls that FOUND
+something (#3497), so `zero_result_calls` sat at 0 and `cleared_threshold` at
+`calls` because of the shape of the code — at any threshold whatsoever. A
+statistic that could not vary was read as a finding about the corpus. It is the
+#2663 failure mode one level up: there the broken readout was a zero, here it
+was a hundred percent, which is far better camouflage.
+
+The reason to measure this arm survives the correction, and is stronger for it.
+`retrieval_logs` records what the ranker scored, never whether the hint was any
+use, so even an honest clear-rate would not settle the question. The ratio these
+two streams produce is the missing half, and without it any threshold change is
+a number picked off a histogram.
+
+Design notes, mirroring `note_usage`:
+  - Writes are fire-and-forget through `background.spawn`, so telemetry never
+    adds latency to — or can break — the surface it observes. This module does
+    NOT carry its own copy of the strong-reference dance; `background` is the
+    one place that gets it right, and a fourth copy is how one of them drifts.
+  - Failures degrade, but never SILENTLY. `report_telemetry_failure` logs at
+    WARNING and drops one AppLog row per process per site. #2663 is the record
+    of this exact subsystem class running at zero for weeks — indistinguishable
+    from "nobody uses this" — because every failure went to `logger.debug`.
+  - Reads (`usage_for_rules`) are awaited and aggregated in one round-trip for
+    a whole page, never per row.
+
+AMBIENT VS RANKED. The note twin splits ranked surfacings from ambient ones
+because `enter_project` and the skill sync put records in front of the agent
+without choosing them, and counting those as surfacings makes recency read as
+popularity (#2477). Rules have exactly that shape: the SessionStart preload,
+`list_always_on_rules`, and every `rules_payload` surface hand over the whole
+applicable set at once, chosen by nobody.
+
+Until 2026-09-03 those bulk surfaces emitted nothing, and this module said so —
+"an empty `AMBIENT_SOURCES` would be machinery pretending to a distinction the
+data does not yet contain". True as far as it went, but it had a consequence
+worth naming, because it is the reason the bucket exists now: the always-on
+set's token cost was certain and its usefulness was UNFALSIFIABLE, permanently
+and by construction. The one surface whose value was actually in question was
+the one surface exempt from the scoreboard that judges every other.
+
+They emit now. The split is the readout-level change the old note promised — a
+`case()`, no migration, because `event` and `source` are plain Text with no
+CHECK constraint. `source` stays granular so a reader can still tell the
+preload from `enter_project` from the ranked arm.
+
+WHY THIS NAMES THE RANKED SOURCES AND THE TWIN NAMES THE AMBIENT ONES. A
+deliberate divergence, on the failure mode rather than on symmetry. Both shapes
+fail silently when someone adds a surface and forgets the list, so the question
+is which list changes more often — and here it is emphatically the ambient one:
+there are TWO ranked rule sources (the write-path arm and the pre-tool arm)
+against the seven bulk ones the preload alone contributes. Ranked sources are
+added when somebody builds a ranker, which is rare and deliberate; bulk ones
+appear whenever a surface hands rules over, which is most of them. Naming the
+rare, slow-moving half means a newly-added bulk surface defaults to
+`ambient`, which merely under-counts it, instead of defaulting to `ranked`,
+which would quietly pad the pull-through denominator with surfacings nobody
+chose and make the arm look imprecise. Same argument #3191 and #3430 make
+against hand-kept lists: keep the list that must be remembered as short and as
+slow-moving as possible.
+"""
+from __future__ import annotations
+
+import logging
+
+from sqlalchemy import case, func, select
+
+from scribe.models import async_session
+from scribe.models.base import iso
+from scribe.models.rule_usage import PULLED, SURFACED, RuleUsageEvent
+from scribe.services.background import report_telemetry_failure, spawn
+
+logger = logging.getLogger(__name__)
+
+# The surfaces that CHOSE the rules they showed. Everything else is ambient —
+# see the module docstring for why the rare half is the half that gets named.
+#
+# Membership is the whole definition of the pull-through denominator: a ranked
+# surfacing is a claim ("this rule may apply to what you are doing") that a pull
+# can confirm or refute, while an ambient one is a delivery nobody decided on.
+# Add a source here only when a ranker picked it.
+RANKED_SOURCES = ("write_path_rule", "pre_tool_rule")
+
+
+def is_ambient(source: str) -> bool:
+    """Was this surfacing a bulk delivery rather than a ranked choice?
+
+    One definition, read by both the per-rule badge readout and the aggregate
+    in `retrieval_telemetry` — the two used to be able to disagree about what
+    "surfaced" counted, which is the class of drift #3246 found across the
+    rules system.
+
+    Sync and pure, per the service canon (#2860), but deliberately PUBLIC where
+    that canon says such helpers stay `_private`. The departure is the point:
+    a module-private copy in each caller is exactly the second definition this
+    exists to prevent.
+    """
+    return source not in RANKED_SOURCES
+
+
+async def _report_failure(site: str) -> None:
+    await report_telemetry_failure("rule_usage", site)
+
+
+async def _insert_events(rows: list[dict]) -> None:
+    """Persist usage rows. Best-effort: failures degrade, visibly."""
+    try:
+        async with async_session() as session:
+            session.add_all([RuleUsageEvent(**row) for row in rows])
+            await session.commit()
+    except Exception:
+        await _report_failure("write")
+
+
+def _schedule(rows: list[dict]) -> None:
+    if not rows:
+        return
+    spawn(_insert_events(rows), site="rule_usage_write")
+
+
+def record_rule_surfaced(
+    *, user_id: int | None, rule_ids: list[int] | set[int], source: str
+) -> None:
+    """Fire-and-forget: record that these rules were shown to the agent.
+
+    Takes the whole delivery at once — one insert per surfacing event, not per
+    rule — because a hint is a single decision and its rows should land
+    together.
+
+    Record what was actually SHOWN, never what was considered. For the ranked
+    arm that means the post-filter hits: it drops what the session already
+    holds (`exclude_rule_ids`) before it speaks, and a rule considered and not
+    shown was not surfaced. Counting those would inflate the denominator with
+    claims the agent never saw, which reads as a precision problem the arm does
+    not have.
+
+    Bulk surfaces pass their whole delivered set, which is the same rule read
+    from the other end — everything in a preload IS shown. `source` is what
+    separates the two afterwards (see `RANKED_SOURCES`); this function does not
+    care which kind it is recording.
+    """
+    try:
+        rows = [
+            {
+                "user_id": user_id,
+                "rule_id": int(rid),
+                "event": SURFACED,
+                "source": source,
+            }
+            for rid in rule_ids
+        ]
+    except Exception:
+        logger.debug("rule usage payload build failed", exc_info=True)
+        return
+    _schedule(rows)
+
+
+def record_rule_pulled(*, user_id: int | None, rule_id: int, source: str) -> None:
+    """Fire-and-forget: record that a rule was opened in full.
+
+    A PULL is somebody choosing to open one record. `list_always_on_rules` and
+    `enter_project` are NOT pulls — they are bulk resident loads that hand over
+    every applicable rule at once, and counting them would swamp the signal
+    with the very ambient delivery the ratio exists to distinguish from.
+    """
+    try:
+        rows = [
+            {
+                "user_id": user_id,
+                "rule_id": int(rule_id),
+                "event": PULLED,
+                "source": source,
+            }
+        ]
+    except Exception:
+        logger.debug("rule usage payload build failed", exc_info=True)
+        return
+    _schedule(rows)
+
+
+def empty_rule_usage() -> dict:
+    """The zero readout — what a rule with no recorded events looks like.
+
+    Callers render this shape unconditionally, so a rule predating the table
+    reads as "never surfaced, never pulled" rather than as a missing key. That
+    distinction matters more here than for notes: every rule in an install
+    predates this table, so for a while "no events" is the normal state and it
+    must not look like a broken readout.
+
+    `surfaced_count` is RANKED surfacings only; `ambient_count` is the bulk
+    deliveries (see `RANKED_SOURCES`). The split is what keeps the badge's
+    "shown often, opened never → dead weight" reading honest: every rule in an
+    always-on set is delivered every session, so an unsplit counter would rank
+    the resident set as the most-surfaced rules in the install purely for being
+    resident.
+    """
+    return {
+        "surfaced_count": 0,
+        "ambient_count": 0,
+        "pull_count": 0,
+        "last_surfaced_at": None,
+        "last_pulled_at": None,
+    }
+
+
+async def usage_for_rules(rule_ids: list[int]) -> dict[int, dict]:
+    """Aggregate usage for a set of rules: {rule_id: {counts + timestamps}}.
+
+    One GROUP BY for the whole page rather than a query per row — this feeds a
+    list view, so the per-row shape would be N+1 by construction. Rules with no
+    events come back with `empty_rule_usage()`, so the caller never has to tell
+    "no events" from "not in the result".
+    """
+    ids = [int(r) for r in rule_ids]
+    out: dict[int, dict] = {rid: empty_rule_usage() for rid in ids}
+    if not ids:
+        return out
+
+    # Classified in SQL so the group stays small: per rule we get at most
+    # (surfaced-ranked, surfaced-ambient, pulled) rather than a row per distinct
+    # source. ONE labelled expression, bound to a variable and reused in the
+    # GROUP BY — a second `case()` instance there renders its own expanding-IN
+    # bind names under asyncpg, so the database sees two DIFFERENT expressions
+    # and rejects the query with a GroupingError. The note twin carries the
+    # same warning for the same reason, and #2663 is what it cost: the
+    # rejection was swallowed and every counter read zero in production while
+    # the writes were landing fine.
+    ambient = case(
+        (RuleUsageEvent.source.notin_(RANKED_SOURCES), True),
+        else_=False,
+    ).label("ambient")
+    try:
+        async with async_session() as session:
+            rows = (
+                await session.execute(
+                    select(
+                        RuleUsageEvent.rule_id,
+                        RuleUsageEvent.event,
+                        func.count().label("n"),
+                        func.max(RuleUsageEvent.created_at).label("last_at"),
+                        ambient,
+                    )
+                    .where(RuleUsageEvent.rule_id.in_(ids))
+                    .group_by(
+                        RuleUsageEvent.rule_id,
+                        RuleUsageEvent.event,
+                        ambient,
+                    )
+                )
+            ).all()
+    except Exception:
+        # A telemetry readout must not be able to break the list it decorates —
+        # but it must say it failed, or a broken readout is indistinguishable
+        # from a corpus nobody uses (#2663).
+        await _report_failure("readout")
+        return out
+
+    for rule_id, event, n, last_at, is_amb in rows:
+        slot = out.get(int(rule_id))
+        if slot is None:
+            continue
+        if event == SURFACED and is_amb:
+            slot["ambient_count"] = int(n)
+        elif event == SURFACED:
+            slot["surfaced_count"] = int(n)
+            slot["last_surfaced_at"] = iso(last_at)
+        elif event == PULLED:
+            # Pulls are pulls regardless of what surfaced the rule — "did
+            # anyone ever open this?" does not depend on how it was found. Both
+            # halves accumulate, so this ADDS rather than assigns: a rule can
+            # now be pulled after a ranked hint and after a preload, and the
+            # split arrives as two rows.
+            slot["pull_count"] = slot["pull_count"] + int(n)
+            latest = iso(last_at)
+            if latest and (slot["last_pulled_at"] or "") < latest:
+                slot["last_pulled_at"] = latest
+    return out

src/scribe/services/rulebooks.py

@@ -23,6 +23,7 @@ from scribe.services.verification import (
 )
 from scribe.services import rule_versions
 from scribe.models.rule_version import RuleVersion
+from scribe.services.rule_usage import record_rule_surfaced
 
 logger = logging.getLogger(__name__)
 
@@ -379,6 +380,10 @@ def _refresh_rule_embedding(rule: Rule) -> None:
     swallowed because a rule that SAVED must not fail on its index refresh —
     a stale vector costs a missed search hit, a raised exception costs the
     write. No running loop (unit tests, scripts) is ordinary, not an error.
+
+    Detaching also means this task races anything that deletes the rule out
+    from under it. That is not handled here: `upsert_rule_embedding` claims
+    the rule's row before touching its vectors, and loses if it can't (#3262).
     """
     try:
         import asyncio
@@ -1391,7 +1396,7 @@ async def get_applicable_rules(
     }
 
 
-def rules_payload(applicable: dict) -> dict:
+def rules_payload(applicable: dict, *, user_id: int | None, source: str) -> dict:
     """The caller-facing shape of a get_applicable_rules() result.
 
     Every surface that hands rules to an agent (enter_project, get_project,
@@ -1402,7 +1407,34 @@ def rules_payload(applicable: dict) -> dict:
     `excluded_always_on` (milestone 297) names the always-on rulebooks this
     project decided NOT to inherit, so the departure is visible wherever the
     rules are.
+
+    IT ALSO RECORDS THE SURFACING, which is why it now takes a caller and a
+    source. Every one of those surfaces is a bulk delivery — the applicable set
+    handed over whole, chosen by nobody — so this is the one place that has to
+    emit for all of them. Doing it per-caller instead would be five sites to
+    remember, and #3430 gap 2 is what that costs: the process→skill sync went
+    un-emitted through an entire dedicated telemetry survey because nothing
+    forced its surface to be accounted for.
+
+    `source` stays the CALLER's name rather than a constant, so the readout can
+    still separate the session handshake from a mid-session milestone read;
+    `RANKED_SOURCES` in `rule_usage` is what folds them back together.
+
+    Emitting from here is safe in a way emitting from `get_applicable_rules`
+    would not be: this function is only ever called to BUILD A REPLY. The two
+    other callers of the rules machinery — the write-path etag arm
+    (`plugin_context`) and `rules_etag_for` — compute a marker and show nobody
+    anything, and counting those would put rules in the denominator that no
+    agent ever saw.
     """
+    record_rule_surfaced(
+        user_id=user_id,
+        rule_ids=(
+            [r["id"] for r in applicable.get("rules", [])]
+            + [r["id"] for r in applicable.get("project_rules", [])]
+        ),
+        source=source,
+    )
     return {
         "applicable_rules": applicable["rules"],
         "applicable_rules_truncated": applicable["truncated"],

tests/helpers.py

@@ -59,14 +59,18 @@ def tool_doc(module: str, name: str) -> str:
     return _re.sub(r"\s+", " ", fn.__doc__)
 
 
-def compiled_sql(element) -> str:
+def compiled_sql(element, dialect=None) -> str:
     """A SQLAlchemy clause or statement rendered as literal SQL text.
 
     For asserting on the shape of a predicate without a database — which is how
     the visibility clauses and the knowledge facets are both tested. Was a
     private copy in each of those modules before #3128 needed a third.
+
+    Pass `dialect` when the assertion is about something only one backend
+    renders — a Postgres row-lock mode, say. The generic dialect is enough for
+    a predicate's shape and would quietly drop the rest.
     """
-    return str(element.compile(compile_kwargs={"literal_binds": True}))
+    return str(element.compile(dialect=dialect, compile_kwargs={"literal_binds": True}))
 
 
 def make_mock_session() -> AsyncMock:

tests/test_embedding_yields_to_a_delete.py

@@ -0,0 +1,118 @@
+"""The embedding refresh must LOSE to a delete, not race it (#3262).
+
+Both upserts replace a record's vectors as delete-then-insert. That takes two
+row locks — the chunk rows, then the parent row via the insert's foreign key —
+in the exact reverse of the order a cascading delete of the parent takes them.
+Postgres calls that a deadlock and kills one side at random, which sometimes
+means killing the user's delete.
+
+These pin the ORDER, not the outcome: the claim on the parent goes first, and
+when the claim fails nothing else in the transaction runs. Compiling the
+statement is the only way to assert on a lock mode without a database — the
+integration twin (test_integration_embedding_yields_to_delete.py) proves the
+behaviour against a real one.
+"""
+from unittest.mock import AsyncMock, MagicMock, patch
+
+from sqlalchemy.dialects import postgresql
+from sqlalchemy.exc import OperationalError
+
+from scribe.services import embeddings as emb
+from tests.helpers import compiled_sql
+
+ONE_VECTOR = [[0.0] * 384]
+
+# The lock mode is a Postgres extension — the generic dialect renders a plain
+# FOR UPDATE and would pass an assertion that proves nothing.
+PG = postgresql.dialect()
+
+
+def _mock_session(lock_result: object = 7, execute_side_effect=None):
+    """A session stand-in whose first execute answers the parent-row claim."""
+    session = MagicMock()
+    claimed = MagicMock()
+    claimed.scalar_one_or_none.return_value = lock_result
+    if execute_side_effect is not None:
+        session.execute = AsyncMock(side_effect=execute_side_effect)
+    else:
+        session.execute = AsyncMock(return_value=claimed)
+    session.commit = AsyncMock()
+    session.add = MagicMock()
+    ctx = MagicMock()
+    ctx.__aenter__ = AsyncMock(return_value=session)
+    ctx.__aexit__ = AsyncMock(return_value=False)
+    return session, ctx
+
+
+def _lock_unavailable() -> OperationalError:
+    """What asyncpg raises through SQLAlchemy when NOWAIT can't take the row."""
+    return OperationalError("SELECT ...", {}, Exception("lock not available"))
+
+
+async def test_a_note_refresh_claims_the_row_before_rewriting_its_vectors():
+    """The claim is FIRST, and it is FOR KEY SHARE NOWAIT.
+
+    FOR KEY SHARE because that is exactly the lock the insert's foreign key
+    takes anyway — it conflicts with a delete of the note and with nothing
+    else, so an ordinary edit is unaffected. NOWAIT because the whole point is
+    to lose immediately rather than queue up behind the delete and hold the
+    chunk rows while doing it.
+    """
+    session, ctx = _mock_session()
+    with (
+        patch.object(emb, "async_session", return_value=ctx),
+        patch.object(emb, "get_embeddings", AsyncMock(return_value=ONE_VECTOR)),
+    ):
+        await emb.upsert_note_embedding(7, 42, "T", "a short body")
+
+    claim, replace = [c.args[0] for c in session.execute.call_args_list][:2]
+    assert compiled_sql(claim, dialect=PG).startswith("SELECT notes.id")
+    assert "FOR KEY SHARE NOWAIT" in compiled_sql(claim, dialect=PG)
+    assert compiled_sql(replace, dialect=PG).startswith("DELETE FROM note_embeddings")
+    session.add.assert_called()
+
+
+async def test_a_rule_refresh_claims_the_row_before_rewriting_its_vectors():
+    """The rule twin — the path the reported deadlock actually took."""
+    session, ctx = _mock_session()
+    with (
+        patch.object(emb, "async_session", return_value=ctx),
+        patch.object(emb, "get_embeddings", AsyncMock(return_value=ONE_VECTOR)),
+    ):
+        await emb.upsert_rule_embedding(9, "T", "a short statement", "on write")
+
+    claim, replace = [c.args[0] for c in session.execute.call_args_list][:2]
+    assert compiled_sql(claim, dialect=PG).startswith("SELECT rules.id")
+    assert "FOR KEY SHARE NOWAIT" in compiled_sql(claim, dialect=PG)
+    assert compiled_sql(replace, dialect=PG).startswith("DELETE FROM rule_embeddings")
+    session.add.assert_called()
+
+
+async def test_a_record_being_deleted_is_left_alone_rather_than_raced():
+    """The claim failing ends the write — it does not fall through to the
+    delete-and-insert that would take the locks in the losing order."""
+    session, ctx = _mock_session(execute_side_effect=_lock_unavailable())
+    with (
+        patch.object(emb, "async_session", return_value=ctx),
+        patch.object(emb, "get_embeddings", AsyncMock(return_value=ONE_VECTOR)),
+    ):
+        await emb.upsert_rule_embedding(9, "T", "a short statement", "on write")
+
+    assert session.execute.await_count == 1, "it stopped at the claim"
+    session.add.assert_not_called()
+    session.commit.assert_not_awaited()
+
+
+async def test_a_record_already_gone_is_not_re_embedded():
+    """A vector inserted for a row that no longer exists is either a foreign
+    key violation or, worse, a resurrected chunk. Nothing to refresh."""
+    session, ctx = _mock_session(lock_result=None)
+    with (
+        patch.object(emb, "async_session", return_value=ctx),
+        patch.object(emb, "get_embeddings", AsyncMock(return_value=ONE_VECTOR)),
+    ):
+        await emb.upsert_note_embedding(7, 42, "T", "a short body")
+
+    assert session.execute.await_count == 1
+    session.add.assert_not_called()
+    session.commit.assert_not_awaited()

tests/test_frontend_request_deadlines.py

@@ -0,0 +1,128 @@
+"""Every request the web UI makes has a deadline (rule 156).
+
+A source-inspection guard in the unit lane — there is no frontend test runner,
+and this is a property of the source rather than of a rendered result, so
+reading the source is the honest way to check it.
+
+WHY. `fetch`'s default is to wait as long as the browser will. That is not a
+long timeout, it is the absence of one, and there is no state a surface can
+render for "pending forever" that is not a lie — the spinner that never
+resolves is indistinguishable from work still in progress. Rule 156 names
+`fetch` specifically:
+
+    When a library's default is "wait indefinitely" — `fetch`, most HTTP
+    clients, a bare `await` on a stream — supplying the deadline is part of
+    using it, not a hardening pass for later.
+
+Before this guard, no request in the app carried one.
+"""
+from __future__ import annotations
+
+import re
+from pathlib import Path
+
+FRONTEND = Path(__file__).resolve().parents[1] / "frontend" / "src"
+CLIENT = FRONTEND / "api" / "client.ts"
+
+
+def _call_text(src: str, start: int) -> str:
+    """The source of one `fetch(...)` call, from its open paren to its close.
+
+    Naive paren balancing. Adequate because every call site here passes an
+    object literal, and a construct complex enough to defeat it is one worth
+    looking at by hand anyway.
+    """
+    depth = 0
+    for i in range(start, len(src)):
+        if src[i] == "(":
+            depth += 1
+        elif src[i] == ")":
+            depth -= 1
+            if depth == 0:
+                return src[start:i + 1]
+    return src[start:]
+
+
+def _fetch_calls() -> list[tuple[Path, str]]:
+    calls: list[tuple[Path, str]] = []
+    for path in list(FRONTEND.rglob("*.ts")) + list(FRONTEND.rglob("*.vue")):
+        src = path.read_text()
+        for m in re.finditer(r"\bfetch\(", src):
+            calls.append((path, _call_text(src, m.end() - 1)))
+    return calls
+
+
+def test_every_fetch_passes_a_signal():
+    """No bare `fetch` anywhere in the frontend.
+
+    Stated on the SIGNAL rather than on a timeout value, because the two
+    legitimate shapes here produce different values and only share this: an
+    ordinary call takes the client's default, a stream bounds its CONNECT and
+    then deliberately runs unbounded, and a bulk transfer passes minutes. What
+    they must all do is pass something.
+    """
+    naked = [
+        f"{path.relative_to(FRONTEND)}: {call[:70]}"
+        for path, call in _fetch_calls()
+        if "signal:" not in call
+    ]
+    assert not naked, (
+        "these fetch calls carry no AbortSignal, so they wait forever "
+        "(rule 156):\n  " + "\n  ".join(naked)
+    )
+
+
+def test_the_client_applies_its_deadline_by_default():
+    """The specific regression that would silently undo this.
+
+    An earlier pass (#3329) made `timeoutMs` OPT-IN and used it at exactly one
+    call site, which left ~330 others waiting forever while the mechanism
+    looked present. Reverting to that shape would not fail the guard above —
+    every call would still reach `fetch` through `request()` — so the default
+    is pinned here separately.
+
+    `??` is the operative character: `opts?.timeoutMs || DEFAULT` would treat
+    an explicit 0 as "use the default", and `opts?.timeoutMs` alone would
+    reinstate the opt-in bug.
+    """
+    src = CLIENT.read_text()
+    assert "opts?.timeoutMs ?? DEFAULT_TIMEOUT_MS" in src, (
+        "request() must fall back to DEFAULT_TIMEOUT_MS — without it the "
+        "deadline is opt-in again and almost nothing opts in"
+    )
+
+
+def test_a_timeout_arrives_as_the_error_shape_callers_already_handle():
+    """Rule 156's second half: expiry surfaces as a NAMED failure.
+
+    A raw `DOMException: TimeoutError` reaches `apiErrorMessage(e, fallback)`
+    as an object with no `body`, so every catch site in the app would print its
+    generic fallback and the timeout would be invisible in exactly the
+    situation it exists to expose. Rethrowing as `ApiError` is what makes the
+    other ~330 call sites report it without being edited.
+    """
+    src = CLIENT.read_text()
+    assert 'e.name === "TimeoutError"' in src, (
+        "request() must recognise a timeout specifically"
+    )
+    assert "new ApiError(CLIENT_TIMEOUT_STATUS" in src, (
+        "a timeout must be rethrown as ApiError so apiErrorMessage can read it"
+    )
+
+
+def test_a_deliberate_cancellation_is_not_reported_as_a_timeout():
+    """Only `TimeoutError` is converted, never `AbortError`.
+
+    A caller that cancelled its own request — a superseded search, a closed
+    stream — must not have that surfaced to the user as a server failure. The
+    guard is that the conversion is gated on the name, which the assertion
+    above already pins; this states the intent so the gate is not "simplified"
+    into catching every abort.
+    """
+    src = CLIENT.read_text()
+    convert = src[src.index("async function request<"):]
+    convert = convert[:convert.index("\n}")]
+    assert "AbortError" not in convert, (
+        "request() must not convert AbortError — a deliberate cancellation is "
+        "not a timeout"
+    )

tests/test_inception_rules.py

@@ -15,14 +15,17 @@ def test_rules_payload_carries_excluded_always_on_as_the_seventh_key():
     out = rules_payload({
         "rules": [], "truncated": False, "subscribed_rulebooks": [],
         "excluded_always_on": [{"id": 1, "title": "Family"}],
-    })
+    }, user_id=1, source="enter_project")
     assert set(out) == {
         "applicable_rules", "applicable_rules_truncated", "subscribed_rulebooks",
         "project_rules", "suppressed_rules", "suppressed_topics", "excluded_always_on",
     }
     assert out["excluded_always_on"] == [{"id": 1, "title": "Family"}]
     # An older applicable dict without the key still renders (empty list).
-    assert rules_payload({"rules": [], "truncated": False, "subscribed_rulebooks": []})["excluded_always_on"] == []
+    assert rules_payload(
+        {"rules": [], "truncated": False, "subscribed_rulebooks": []},
+        user_id=1, source="enter_project",
+    )["excluded_always_on"] == []
 
 
 def test_list_always_on_rules_service_and_tool_take_a_project_id():

tests/test_instruction_surfaces_agree.py

@@ -195,6 +195,46 @@ def test_displaced_topics_live_on_a_delivered_surface():
     )
 
 
+# The SECOND pull (milestone 333 step 3). `list_always_on_rules()` fetches the
+# resident tier; this one says that tier is not all of them, and that a
+# conditional rule has to be gone looking for. However a surface words the
+# surrounding prose, it names the call.
+RETRIEVE = 'content_type="rule"'
+
+
+def test_every_session_start_surface_states_the_conditional_retrieval():
+    """The push/pull asymmetry, one level in.
+
+    The tests above pin that a session PULLS the resident rules rather than
+    trusting the SessionStart push. This pins the same shape between the two
+    TIERS: an always-on rule is delivered, a conditional one is retrieved, and
+    a surface that states only the first leaves a session reading its loaded
+    set as the whole rulebook.
+
+    That reading is wrong in the direction that costs something. "Nothing was
+    pushed" and "no rule applies" are different claims, and only one of them
+    has been checked — the same asymmetry as #2198, now between tiers instead
+    of between channels.
+
+    It is also what made the always-on tier the only one that worked, on any
+    install rather than this one (rule 115). A rule nothing retrieves has to be
+    resident to bind at all, so every rule worth keeping becomes resident; and
+    a resident rule costs tokens in every session forever, so a rulebook that
+    only delivers cannot grow past what one session can hold. Retrieval is what
+    lifts that ceiling — and it only fires if something asks.
+    """
+    missing = []
+    for path in SESSION_START_SURFACES:
+        if RETRIEVE not in path.read_text():
+            missing.append(str(path.relative_to(ROOT)))
+    assert not missing, (
+        f"these surfaces state the always-on pull but never tell the agent to "
+        f"retrieve a conditional rule ({RETRIEVE}): {missing}. A session that "
+        f"reads its loaded set as the whole rulebook will act on \"I was not "
+        f"told\" as if it meant \"there is no rule\" (milestone 333 step 3)."
+    )
+
+
 def test_no_surface_names_the_push_without_stating_the_pull():
     """The exact shape #2497 took.
 

tests/test_integration_backup_rule_usage_roundtrip.py

@@ -0,0 +1,294 @@
+"""Real-Postgres round trip for rule_usage_events (milestone 333 step 1).
+
+**This file is the reason the table exists.** `rule_usage_events` could have
+been a `rule_id` column on `note_usage_events` — the row carries no
+note-specific field and the readout is the same shape, which is the strongest
+case for sharing that note #3163 admits. What decided against it is identity at
+restore, and that is a claim only a real round trip can support.
+
+The failure it guards is the quiet kind. `note_usage_events`'s importer maps
+`note_id` through `note_id_map`; a rule id parked in that column comes back
+attached to whatever note happens to hold that number in the target database.
+Not dropped — REATTACHED. The restore reports success, the counters are
+populated, and every one of them is about the wrong record. Nothing downstream
+can detect it, because a usage row has no other field to disagree with.
+
+So the assertions below are about WHICH MAP resolved the id, and they are
+written to fail if the answer ever becomes "the note one" or "neither".
+
+Same shape as `test_integration_backup_rule_version_roundtrip.py`, which guards
+`rule_versions` against #3182's `arose_from_id` trap on the same seam.
+"""
+import pytest
+import pytest_asyncio
+from sqlalchemy import select
+
+from scribe.models import async_session
+from scribe.models.note import Note
+from scribe.models.rule_usage import PULLED, SURFACED, RuleUsageEvent
+from scribe.models.rulebook import Rule, Rulebook, RulebookTopic
+from scribe.models.user import User
+from scribe.services import backup
+from tests.helpers import ensure_user
+
+pytestmark = [pytest.mark.integration, pytest.mark.usefixtures("_dispose_engine")]
+
+OWNER_USERNAME = "rule_usage_roundtrip_owner"
+RESTORED_USERNAME = "rule_usage_roundtrip_restored"
+
+
+async def _purge_books(username: str) -> None:
+    """user -> rulebook -> topic -> rule is ON DELETE CASCADE the whole way,
+    so dropping the books clears the rules this file made.
+
+    `rule_usage_events` is deliberately FK-FREE, so its rows do NOT cascade —
+    that is the property under test elsewhere (telemetry outlives what it
+    describes). They are cleared explicitly below.
+    """
+    async with async_session() as s:
+        users = (await s.execute(
+            select(User).where(User.username == username)
+        )).scalars().all()
+        for user in users:
+            books = (await s.execute(
+                select(Rulebook).where(Rulebook.owner_user_id == user.id)
+            )).scalars().all()
+            for book in books:
+                await s.delete(book)
+            for note in (await s.execute(
+                select(Note).where(Note.user_id == user.id)
+            )).scalars().all():
+                await s.delete(note)
+        await s.commit()
+
+
+async def _purge_usage(rule_ids: set[int]) -> None:
+    if not rule_ids:
+        return
+    async with async_session() as s:
+        for ev in (await s.execute(
+            select(RuleUsageEvent).where(RuleUsageEvent.rule_id.in_(rule_ids))
+        )).scalars().all():
+            await s.delete(ev)
+        await s.commit()
+
+
+async def _purge_restored() -> None:
+    await _purge_books(RESTORED_USERNAME)
+    async with async_session() as s:
+        for user in (await s.execute(
+            select(User).where(User.username == RESTORED_USERNAME)
+        )).scalars().all():
+            await s.delete(user)
+        await s.commit()
+
+
+@pytest_asyncio.fixture(autouse=True)
+async def _no_leftovers():
+    """SETUP ONLY — see the sibling file for why a database call after a
+    `yield` here orphans a pooled connection and breaks unrelated tests."""
+    await _purge_restored()
+    await _purge_books(OWNER_USERNAME)
+
+
+@pytest_asyncio.fixture
+async def source():
+    """One rule with a surfaced/pulled pair — plus a NOTE that will hold the
+    rule's id in the restored database.
+
+    That note is the whole trick. Without it, a restore that ran rule ids
+    through `note_id_map` would simply drop them and the test would read as a
+    pass-by-absence. With it, the wrong map produces a plausible, populated,
+    entirely wrong result — which is the failure actually being guarded.
+    """
+    async with async_session() as s:
+        owner = await ensure_user(s, OWNER_USERNAME)
+        uid = owner.id
+        await s.commit()
+
+    async with async_session() as s:
+        book = Rulebook(owner_user_id=uid, title="Environment facts")
+        s.add(book)
+        await s.flush()
+        topic = RulebookTopic(rulebook_id=book.id, title="ci")
+        s.add(topic)
+        await s.flush()
+        rule = Rule(
+            topic_id=topic.id,
+            title="A wait with no deadline is a bug",
+            statement="Every wait on something that can fail to answer carries one.",
+        )
+        s.add(rule)
+        # A note in the same export, so the target database has a note id to
+        # collide with. Its own id is irrelevant; what matters is that the
+        # note map is populated and would resolve to something.
+        note = Note(user_id=uid, title="a note that must not receive rule telemetry",
+                    body="decoy")
+        s.add(note)
+        await s.flush()
+        s.add_all([
+            RuleUsageEvent(
+                user_id=uid, rule_id=rule.id,
+                event=SURFACED, source="write_path_rule",
+            ),
+            RuleUsageEvent(
+                user_id=uid, rule_id=rule.id,
+                event=PULLED, source="mcp_get_rule",
+            ),
+            # No actor. The arm can fire for an unauthenticated hook call, and
+            # a user who later leaves must not take the evidence with them.
+            RuleUsageEvent(
+                user_id=None, rule_id=rule.id,
+                event=SURFACED, source="write_path_rule",
+            ),
+        ])
+        await s.commit()
+        book_id, rule_id, note_id = book.id, rule.id, note.id
+
+    async with async_session() as s:
+        user_rows = backup._user_rows(
+            [(await s.execute(select(User).where(User.id == uid))).scalars().one()]
+        )
+        book_rows = backup._rulebook_rows(
+            [(await s.execute(select(Rulebook).where(Rulebook.id == book_id)))
+             .scalars().one()]
+        )
+        topic_rows = backup._topic_rows(
+            (await s.execute(
+                select(RulebookTopic).where(RulebookTopic.rulebook_id == book_id)
+            )).scalars().all()
+        )
+        rule_rows = backup._rule_rows(
+            [(await s.execute(select(Rule).where(Rule.id == rule_id))).scalars().one()]
+        )
+        note_rows = backup._note_rows(
+            [(await s.execute(select(Note).where(Note.id == note_id))).scalars().one()]
+        )
+        usage_rows = backup._rule_usage_event_rows(
+            (await s.execute(
+                select(RuleUsageEvent).where(RuleUsageEvent.rule_id == rule_id)
+                .order_by(RuleUsageEvent.id)
+            )).scalars().all()
+        )
+    user_rows[0]["username"] = RESTORED_USERNAME
+
+    yield {
+        "payload": {
+            "version": backup.BACKUP_VERSION,
+            "users": user_rows,
+            "rulebooks": book_rows,
+            "rulebook_topics": topic_rows,
+            "rules": rule_rows,
+            "notes": note_rows,
+            "rule_usage_events": usage_rows,
+        },
+        "source_rule_id": rule_id,
+        "source_user_id": uid,
+    }
+
+    await _purge_usage({rule_id})
+    async with async_session() as s:
+        book = await s.get(Rulebook, book_id)
+        if book is not None:
+            await s.delete(book)
+        note = await s.get(Note, note_id)
+        if note is not None:
+            await s.delete(note)
+        await s.commit()
+
+
+@pytest_asyncio.fixture
+async def restored(source):
+    await backup.restore_full_backup(source["payload"])
+    async with async_session() as s:
+        user = (await s.execute(
+            select(User).where(User.username == RESTORED_USERNAME)
+        )).scalars().first()
+        assert user is not None, "the payload's user was not restored"
+        book = (await s.execute(
+            select(Rulebook).where(Rulebook.owner_user_id == user.id)
+        )).scalars().one()
+        topic = (await s.execute(
+            select(RulebookTopic).where(RulebookTopic.rulebook_id == book.id)
+        )).scalars().one()
+        rule = (await s.execute(
+            select(Rule).where(Rule.topic_id == topic.id)
+        )).scalars().one()
+        note = (await s.execute(
+            select(Note).where(Note.user_id == user.id)
+        )).scalars().one()
+        events = (await s.execute(
+            select(RuleUsageEvent).where(RuleUsageEvent.rule_id == rule.id)
+            .order_by(RuleUsageEvent.id)
+        )).scalars().all()
+    yield {
+        "user": user, "rule": rule, "note": note,
+        "events": events, "source": source,
+    }
+
+    await _purge_usage({rule.id})
+    await _purge_restored()
+
+
+async def test_every_event_comes_back(restored):
+    """The count first: every shape assertion below reads the same on an empty
+    list, so without this a restore that dropped all three would pass them."""
+    assert len(restored["events"]) == 3
+
+
+async def test_the_events_attach_to_the_RESTORED_rule(restored):
+    """The remap, on the column that matters."""
+    new_rule_id = restored["rule"].id
+    source_rule_id = restored["source"]["source_rule_id"]
+    assert new_rule_id != source_rule_id, (
+        "the restore reused the source id, so this test cannot tell a remap "
+        "from a copy — the fixture is not proving what it claims"
+    )
+    assert {e.rule_id for e in restored["events"]} == {new_rule_id}
+
+
+async def test_no_event_landed_on_the_note_id(restored):
+    """THE ONE THIS TABLE EXISTS FOR.
+
+    If `rule_id` were ever resolved through `note_id_map` — the shape it would
+    have had as a column on `note_usage_events` — these rows would come back
+    pointing at the restored NOTE's id. Populated, plausible, and describing a
+    record that was never surfaced.
+    """
+    note_id = restored["note"].id
+    landed_on_note = [e for e in restored["events"] if e.rule_id == note_id]
+    assert not landed_on_note, (
+        f"{len(landed_on_note)} usage event(s) resolved to the note's id "
+        f"({note_id}) instead of the rule's. The rule id went through the "
+        "note map — telemetry that is wrong rather than missing, and that "
+        "nothing downstream can detect."
+    )
+
+
+async def test_the_actor_is_remapped_and_a_missing_one_survives(restored):
+    """`user_id` is an id in the source database too — the same trap one
+    column over. And the actorless row must not be dropped: the arm can fire
+    for an unauthenticated hook call, so requiring an actor would discard the
+    surfacings of exactly the surface being measured."""
+    attributed = [e for e in restored["events"] if e.user_id is not None]
+    orphaned = [e for e in restored["events"] if e.user_id is None]
+    assert len(attributed) == 2
+    assert len(orphaned) == 1, (
+        "the event with no actor did not come back. Telemetry outlives the "
+        "account it was recorded for; dropping it silently lowers the "
+        "surfaced count that the pull-through ratio divides by."
+    )
+    assert {e.user_id for e in attributed} == {restored["user"].id}
+    assert restored["user"].id != restored["source"]["source_user_id"]
+
+
+async def test_the_event_and_source_survive(restored):
+    """The two fields the ratio is computed from. A restore that kept the rows
+    and lost these would preserve a count of nothing in particular."""
+    pairs = {(e.event, e.source) for e in restored["events"]}
+    assert pairs == {
+        (SURFACED, "write_path_rule"),
+        (PULLED, "mcp_get_rule"),
+    }
+    assert sum(1 for e in restored["events"] if e.event == SURFACED) == 2
+    assert sum(1 for e in restored["events"] if e.event == PULLED) == 1

tests/test_integration_embedding_yields_to_delete.py

@@ -0,0 +1,173 @@
+"""#3262 against a real Postgres: the embedder loses the race, it doesn't run it.
+
+The reported failure was a deadlock — `DELETE FROM rulebooks` killed by the
+server while a detached `upsert_rule_embedding` held the other half of the
+cycle. It cannot be reproduced with mocks, because there is nothing to
+deadlock: the whole bug lives in the ORDER two transactions take two row
+locks, which only a lock manager can adjudicate.
+
+So each test here holds a real delete open in one transaction and calls the
+embedder in another. What is being pinned is that the embedder RETURNS —
+promptly, having written nothing. Before the fix it would sit on the chunk
+rows waiting for a delete that is itself waiting on the insert's foreign key,
+and the test would hang rather than fail, which is why every call carries a
+deadline (rule 156).
+"""
+import asyncio
+from unittest.mock import AsyncMock, patch
+
+import pytest
+import pytest_asyncio
+from sqlalchemy import delete, select
+
+from scribe.models import async_session
+from scribe.models.embedding import NoteEmbedding, RuleEmbedding
+from scribe.models.note import Note
+from scribe.models.rulebook import Rulebook
+from scribe.services import embeddings as emb
+from scribe.services import rulebooks as rulebooks_svc
+from tests.helpers import ensure_user
+
+pytestmark = [pytest.mark.integration, pytest.mark.usefixtures("_dispose_engine")]
+
+OWNER_USERNAME = "embed_lock_owner"
+
+# Generous, because the assertion is "it did not block indefinitely", not "it
+# was fast". A machine under load must not turn this into a flake; a genuinely
+# blocked embedder never returns at all, so no honest run comes near this.
+YIELD_DEADLINE_SECONDS = 20
+
+# What the embedder would write if it wrongly went ahead. Distinct from the
+# text the fixture's own create_* wrote, so the assertion cannot be satisfied
+# by rows that were already there.
+SENTINEL = "sentinelvector"
+
+ONE_VECTOR = [[0.0] * 384]
+
+# The fixture's own embedding task runs the REAL embedder, which either loads a
+# model or gives up; both are bounded well inside this.
+SETTLE_DEADLINE_SECONDS = 30
+
+
+@pytest_asyncio.fixture
+async def seeded():
+    """A rule and a note to race against.
+
+    CLEANED AT SETUP, NOT TEARDOWN — the same constraint #3241 hit and the
+    reason this file exists. `create_rule` fires its own detached embedding
+    task; a teardown that deleted the rulebook would be racing exactly the
+    thing under test, on a loop that is closing.
+    """
+    async with async_session() as s:
+        owner = await ensure_user(s, OWNER_USERNAME)
+        uid = owner.id
+        await s.commit()
+        for book in (await s.execute(
+            select(Rulebook).where(Rulebook.owner_user_id == uid)
+        )).scalars().all():
+            await s.delete(book)
+        for note in (await s.execute(
+            select(Note).where(Note.user_id == uid)
+        )).scalars().all():
+            await s.delete(note)
+        await s.commit()
+
+    book = await rulebooks_svc.create_rulebook(uid, "Lock fixtures")
+    topic = await rulebooks_svc.create_topic(book.id, uid, "locks")
+    rule = await rulebooks_svc.create_rule(
+        topic.id, uid, "A rule with vectors",
+        "Something for the embedder to index.",
+    )
+    async with async_session() as s:
+        note = Note(user_id=uid, title="A note with vectors", body="Body text.")
+        s.add(note)
+        await s.commit()
+        note_id = note.id
+
+    await _settle_detached_writes()
+    return {"uid": uid, "book_id": book.id, "rule_id": rule.id, "note_id": note_id}
+
+
+async def _settle_detached_writes() -> None:
+    """Let `create_rule`'s own fire-and-forget embedding task finish.
+
+    It is the same detached write these tests are about, aimed at the same
+    rule, and left in flight it would land in the middle of an assertion about
+    that rule's rows. Bounded, and a timeout is not a failure — the tests below
+    carry their own deadlines, and this is only tidying the start line.
+    """
+    pending = [t for t in asyncio.all_tasks() if t is not asyncio.current_task()]
+    if pending:
+        await asyncio.wait(pending, timeout=SETTLE_DEADLINE_SECONDS)
+
+
+async def _rule_chunks(rule_id: int) -> list[str]:
+    async with async_session() as s:
+        return list((await s.execute(
+            select(RuleEmbedding.chunk_text).where(RuleEmbedding.rule_id == rule_id)
+        )).scalars().all())
+
+
+async def _note_chunks(note_id: int) -> list[str]:
+    async with async_session() as s:
+        return list((await s.execute(
+            select(NoteEmbedding.chunk_text).where(NoteEmbedding.note_id == note_id)
+        )).scalars().all())
+
+
+async def test_a_rule_refresh_yields_to_a_delete_cascading_from_its_rulebook(seeded):
+    """The reported case, exactly: the delete lands on the RULEBOOK and reaches
+    the rule through two cascades, which is why nothing on the rule's own write
+    path could have seen it coming."""
+    async with async_session() as blocker:
+        # Uncommitted on purpose — the cascade's locks are held for as long as
+        # this transaction stays open, which is the state the embedder must
+        # decline to fight over.
+        await blocker.execute(delete(Rulebook).where(Rulebook.id == seeded["book_id"]))
+        try:
+            with patch.object(emb, "get_embeddings", AsyncMock(return_value=ONE_VECTOR)):
+                await asyncio.wait_for(
+                    emb.upsert_rule_embedding(
+                        seeded["rule_id"], SENTINEL, f"{SENTINEL} statement",
+                    ),
+                    timeout=YIELD_DEADLINE_SECONDS,
+                )
+        finally:
+            await blocker.rollback()
+
+    assert not any(SENTINEL in text for text in await _rule_chunks(seeded["rule_id"])), \
+        "the embedder wrote into a rule that was being deleted"
+
+
+async def test_a_note_refresh_yields_to_a_delete_of_the_note(seeded):
+    """The note twin, which #3262 recorded as unverified. Notes are soft-deleted
+    day to day, so the hard delete a trash purge issues is the one that can put
+    a lock on the row while a refresh is in flight."""
+    async with async_session() as blocker:
+        await blocker.execute(delete(Note).where(Note.id == seeded["note_id"]))
+        try:
+            with patch.object(emb, "get_embeddings", AsyncMock(return_value=ONE_VECTOR)):
+                await asyncio.wait_for(
+                    emb.upsert_note_embedding(
+                        seeded["note_id"], seeded["uid"], SENTINEL, f"{SENTINEL} body",
+                    ),
+                    timeout=YIELD_DEADLINE_SECONDS,
+                )
+        finally:
+            await blocker.rollback()
+
+    assert not any(SENTINEL in text for text in await _note_chunks(seeded["note_id"])), \
+        "the embedder wrote into a note that was being deleted"
+
+
+async def test_an_uncontended_refresh_still_writes(seeded):
+    """The guard against the cheapest possible false pass: a claim that never
+    succeeds would satisfy both tests above while quietly ending semantic
+    search."""
+    with patch.object(emb, "get_embeddings", AsyncMock(return_value=ONE_VECTOR)):
+        await emb.upsert_rule_embedding(
+            seeded["rule_id"], SENTINEL, f"{SENTINEL} statement",
+        )
+
+    assert any(SENTINEL in text for text in await _rule_chunks(seeded["rule_id"])), \
+        "an unlocked rule was not embedded"

tests/test_note_usage.py

@@ -154,7 +154,8 @@ async def test_unscored_location_arms_are_recorded(lookups, expected_source):
         patch.object(
             plugin_context,
             "get_writepath_config",
-            AsyncMock(return_value={"enabled": True, "threshold": 0.55, "top_k": 3}),
+            AsyncMock(return_value={"enabled": True, "threshold": 0.55, "top_k": 3,
+                                    "rule_threshold": 0.72}),
         ),
         patch.object(
             plugin_context.snippets_svc,

tests/test_plugin_shipped_set.py

@@ -0,0 +1,250 @@
+"""One definition of what SHIPS in the plugin, and the drift guards on it.
+
+WHAT THIS IS ABOUT (#3127 §3, milestone 334 step 2). Scribe publishes two
+artifacts. `plugin/` is not in the Docker image — installs fetch it from this
+repo through `.claude-plugin/marketplace.json`, so **a push IS the release**,
+with no build step in between. That makes "which files reach an install?" a
+question with real consequences, and it has been answered wrong twice:
+
+  - #2198 — `plugin/**` was in no `paths:` filter, so four broken hooks
+    reached live installs having triggered no CI at all.
+  - #2209 — the fix for that shipped and still could not reach an install,
+    because the manifest version had not moved.
+
+The set lives in `scripts/check_plugin.py`. Its second consumer is the
+workflow's `paths:` trigger, which is YAML and cannot import Python — so the
+"one definition" is held together by the drift tests here rather than by an
+import. That is the honest shape, and it is why these tests exist at all.
+
+The exclusion tests are the load-bearing half. Without the manifest-`version`
+exclusion the version check is CIRCULAR: bumping the version edits a file
+inside `plugin/`, which then reads as the content change that justifies the
+bump. Every bump passes, no bump ever fails, and the check has proved nothing
+while looking green.
+"""
+import json
+import pathlib
+import re
+
+import pytest
+
+from scripts.check_plugin import (
+    DERIVERS,
+    SHIPPED_PATHS,
+    manifest_differs_beyond_version,
+)
+
+ROOT = pathlib.Path(__file__).resolve().parents[1]
+CI = ROOT / ".forgejo/workflows/ci.yml"
+
+
+def trigger_paths() -> list[str]:
+    """The `paths:` list under the workflow's push trigger.
+
+    Parsed with a regex rather than a YAML library, matching what
+    test_version_endpoint.py already does with this file — the alternative is
+    adding PyYAML as a dependency for one assertion. Raises rather than
+    returning empty: a silent no-op here would defeat the point of the file.
+    """
+    text = CI.read_text()
+    block = re.search(r"^    paths:\n((?:(?:      [-#].*)?\n)+)", text, re.M)
+    if block is None:
+        raise AssertionError("could not find the push trigger's `paths:` block")
+    found = re.findall(r'^      - "([^"]+)"', block.group(1), re.M)
+    if not found:
+        raise AssertionError("the `paths:` block parsed to zero entries")
+    return found
+
+
+# ── The set itself ─────────────────────────────────────────────────────────
+
+
+def test_every_shipped_path_exists():
+    """A set naming something that isn't there is not a definition of anything."""
+    for path in SHIPPED_PATHS:
+        assert (ROOT / path).exists(), f"SHIPPED_PATHS names {path}, which does not exist"
+
+
+def test_every_shipped_path_triggers_ci():
+    """#2198's exact hole, stated as an assertion.
+
+    Directional on purpose: the trigger is a superset (it also fires on
+    `src/**`, `tests/**` and friends). What must never happen is a path that
+    reaches an install and fires no lane.
+    """
+    triggers = trigger_paths()
+    for path in SHIPPED_PATHS:
+        covered = any(t == path or t.startswith(f"{path}/") for t in triggers)
+        assert covered, (
+            f"{path} ships to installs but no `paths:` entry covers it — "
+            f"changes there would reach a live install having run no CI (#2198)"
+        )
+
+
+def test_the_checker_itself_triggers_ci():
+    """Changing the checks must re-run them.
+
+    Not a member of the shipped set — a checker decides whether the lane goes
+    red, not what any artifact reports — but a change to it that runs no lane
+    is the same silence by a different route.
+    """
+    assert "scripts/check_plugin.py" in trigger_paths()
+
+
+def test_no_trigger_path_names_something_that_does_not_exist():
+    """The guard that catches scaffolding outliving its subsystem.
+
+    `fable-mcp/**` sat in this list for three months after the directory was
+    deleted (commit 91bafb6, 2026-05-27), and `assets/**` named a path that
+    never existed at all. Neither ever failed anything — a `paths:` entry
+    matching nothing simply never fires — which is precisely why a list kept
+    by hand drifts and nobody finds out.
+    """
+    missing = [
+        entry for entry in trigger_paths()
+        if not (ROOT / re.sub(r"/\*\*$", "", entry)).exists()
+    ]
+    assert not missing, (
+        f"`paths:` names {missing}, which do not exist in the repo. A trigger "
+        f"that matches nothing is silent, so it survives every review."
+    )
+
+
+def test_every_deriver_exists():
+    """§3's table, kept honest.
+
+    The point of the table is that the next artifact is a one-line addition
+    (milestone 334 step 3 adds the plugin's mint script). A row pointing at a
+    file that has moved would make the table read as complete when it is not.
+    """
+    for path, artifacts in DERIVERS.items():
+        assert (ROOT / path).exists(), f"DERIVERS names {path}, which does not exist"
+        assert artifacts, f"DERIVERS[{path}] names no artifact"
+
+
+# ── The exclusion — the half that makes the version check mean anything ────
+
+
+def manifest(**fields) -> str:
+    base = {
+        "name": "scribe",
+        "description": "d",
+        "version": "0.1.48",
+        "mcpServers": {"scribe": {"type": "http", "url": "${user_config.api_endpoint}/mcp"}},
+        "userConfig": {"api_endpoint": {"type": "string"}},
+    }
+    base.update(fields)
+    return json.dumps(base)
+
+
+def test_a_version_only_change_is_NOT_a_content_change():
+    """THE assertion. Without it the version check is self-satisfying: the
+    bump edits `plugin.json`, which lives inside `plugin/`, so the bump is its
+    own justification and every bump passes."""
+    assert manifest_differs_beyond_version(
+        manifest(version="2026.09.01.0512"), manifest(version="0.1.48")
+    ) is False
+
+
+def test_an_identical_manifest_is_not_a_change():
+    assert manifest_differs_beyond_version(manifest(), manifest()) is False
+
+
+@pytest.mark.parametrize("field,value", [
+    ("userConfig", {"api_endpoint": {"type": "string", "title": "changed"}}),
+    ("mcpServers", {"scribe": {"type": "http", "url": "elsewhere"}}),
+    ("description", "a different description"),
+    ("name", "renamed"),
+])
+def test_every_OTHER_manifest_field_still_demands_a_new_version(field, value):
+    """Why the exclusion is one FIELD and never the whole file.
+
+    `plugin.json` carries description, mcpServers and userConfig alongside the
+    version, and all of them reach an install. Excluding the file wholesale
+    would mean a userConfig-only edit computes an unchanged version and never
+    refreshes — #2209 again, with a narrower trigger and the same silence.
+    """
+    assert manifest_differs_beyond_version(manifest(**{field: value}), manifest()) is True
+
+
+def test_reformatting_is_not_a_content_change():
+    """Parsed objects, not text. Whitespace and key order are not content, and
+    a check that treated them as such would demand a version for a re-indent."""
+    data = json.loads(manifest())
+    reordered = {k: data[k] for k in reversed(list(data))}
+    assert manifest_differs_beyond_version(
+        json.dumps(reordered, indent=4), json.dumps(data, separators=(",", ":"))
+    ) is False
+
+
+@pytest.mark.parametrize("bad", ["", "{not json", "[]", '"a string"', "null"])
+def test_unreadable_input_demands_a_new_version(bad):
+    """The conservative direction, chosen deliberately.
+
+    A spurious bump costs one cache refresh. A missed one is #2209 — the fix
+    reaches the repo and stops there, and the only detector is a human saying
+    "I don't think it updated."
+    """
+    assert manifest_differs_beyond_version(bad, manifest()) is True
+    assert manifest_differs_beyond_version(manifest(), bad) is True
+
+
+def test_a_manifest_appearing_or_vanishing_is_a_change():
+    """None means the file is absent at that ref — a real difference, and not
+    the same thing as unreadable."""
+    assert manifest_differs_beyond_version(None, manifest()) is True
+    assert manifest_differs_beyond_version(manifest(), None) is True
+
+
+# ── The reader that joins the exclusion to git ─────────────────────────────
+
+
+def test_shipped_content_changed_reports_a_version_only_commit_as_unchanged(monkeypatch):
+    """End to end through the git seam, with git stubbed.
+
+    The unit above proves the comparison; this proves it is actually WIRED to
+    the path that `check_version_is_minted` reads. A correct helper nobody calls
+    would leave the circular check exactly as it was.
+    """
+    from scripts import check_plugin
+
+    monkeypatch.setattr(
+        check_plugin, "_git",
+        lambda *a: (0, "plugin/.claude-plugin/plugin.json"),
+    )
+    monkeypatch.setattr(
+        check_plugin, "manifest_text",
+        lambda ref=None: manifest(version="2026.09.01.0512" if ref is None else "0.1.48"),
+    )
+    changed, paths = check_plugin.shipped_content_changed("origin/main")
+    assert changed is False
+    assert paths == ["plugin/.claude-plugin/plugin.json"]
+
+
+def test_shipped_content_changed_reports_a_hook_edit_as_changed(monkeypatch):
+    """The guard against an exclusion that swallowed everything — a check that
+    can never fire is indistinguishable from one that is broken."""
+    from scripts import check_plugin
+
+    monkeypatch.setattr(
+        check_plugin, "_git",
+        lambda *a: (0, "plugin/hooks/scribe_session_context.sh"),
+    )
+    changed, paths = check_plugin.shipped_content_changed("origin/main")
+    assert changed is True
+    assert paths == ["plugin/hooks/scribe_session_context.sh"]
+
+
+def test_a_failed_diff_is_None_and_never_False(monkeypatch):
+    """Could-not-tell and nothing-changed must not collapse into one value.
+
+    #2663 is the precedent: a read that failed inside a broad except reported
+    the same zero as a genuinely empty window, and every counter read zero for
+    weeks with nothing to distinguish the two.
+    """
+    from scripts import check_plugin
+
+    monkeypatch.setattr(check_plugin, "_git", lambda *a: (128, "fatal: bad revision"))
+    changed, paths = check_plugin.shipped_content_changed("origin/main")
+    assert changed is None
+    assert paths == []

tests/test_plugin_version_mint.py

@@ -0,0 +1,287 @@
+"""The plugin's version is MINTED, and CI is the control that it moved.
+
+WHAT THIS IS ABOUT (milestone 334 step 3). `plugin/` ships straight from this
+git repo — no build step, so no moment at which CI could stamp a version in.
+The value is therefore minted by a script before the commit, and CI's job is
+not to produce it but to prove it moved when it had to.
+
+THE DIVERGENCE THESE GUARD. Two artifacts in one repo derive their versions
+from different clocks, on purpose:
+
+    server image   name from COMMIT time, ordering key from BUILD time
+    plugin         one value, from MINT time
+
+#3127 §2 prescribes commit time so two lanes building one source report one
+string. The plugin has one lane and no build, so that reason does not reach
+it. "Let's make these consistent" is the obvious tidy-up and it breaks
+whichever artifact loses — which is why the difference is pinned here rather
+than only explained in a comment.
+
+The trade mint time makes — you cannot recompute the value from history, only
+verify it moved — is acceptable ONLY because #3325 established that the
+installer's refresh test is `===` with no ordering anywhere. Where a
+comparator orders, an unreproducible version would be unverifiable too.
+"""
+import ast
+import json
+import pathlib
+import re
+from datetime import datetime, timedelta, timezone
+
+import pytest
+
+from scripts import check_plugin
+from scripts.mint_plugin_version import VERSION_RE, mint, rewrite
+
+MINT_SRC = pathlib.Path(check_plugin.ROOT) / "scripts" / "mint_plugin_version.py"
+
+
+@pytest.fixture(autouse=True)
+def _reset_failures():
+    """`check_plugin.fail` appends to a module global; without this a failing
+    assertion in one test would be visible from the next."""
+    check_plugin.failures.clear()
+    yield
+    check_plugin.failures.clear()
+
+
+def fake_manifest(version: str = "2026.09.01.2252") -> str:
+    return json.dumps(
+        {"name": "scribe", "description": "d", "version": version,
+         "userConfig": {"api_endpoint": {"type": "string"}}},
+        indent=2,
+    )
+
+
+# ── The mint ───────────────────────────────────────────────────────────────
+
+
+@pytest.mark.parametrize("when,expected", [
+    # THE midnight case, which #3127 checklist 10 names by hand. An unpadded
+    # `%-H%M` renders this hour as `0` and silently shortens the string.
+    (datetime(2026, 1, 5, 0, 0, tzinfo=timezone.utc), "2026.01.05.0000"),
+    (datetime(2026, 1, 5, 0, 9, tzinfo=timezone.utc), "2026.01.05.0009"),
+    (datetime(2026, 12, 31, 23, 59, tzinfo=timezone.utc), "2026.12.31.2359"),
+    (datetime(2026, 9, 1, 22, 52, tzinfo=timezone.utc), "2026.09.01.2252"),
+])
+def test_the_mint_zero_pads_every_field(when, expected):
+    assert mint(when) == expected
+    assert VERSION_RE.match(mint(when))
+
+
+def test_the_mint_is_UTC_not_local():
+    """A local-time mint would make the value depend on who ran it — two people
+    minting the same minute would disagree, and the string is the artifact's
+    identity."""
+    utc = datetime(2026, 9, 1, 22, 52, tzinfo=timezone.utc)
+    east = utc.astimezone(timezone(timedelta(hours=9)))
+    assert mint(east) == mint(utc) == "2026.09.01.2252"
+
+
+def test_the_mint_reads_a_CLOCK_and_never_git():
+    """The clock divergence from the server image, asserted structurally.
+
+    Mint time is only meaningful if nothing consults history — the moment this
+    script shells out to git it has quietly become a commit-time deriver, and
+    the two artifacts' clocks have been "made consistent" without anyone
+    deciding to. That change would pass every other test in this file.
+
+    Asserted over the AST rather than the text, because the module docstring
+    discusses git at length explaining why it is absent. This looks for USE,
+    not mention.
+    """
+    tree = ast.parse(MINT_SRC.read_text())
+
+    imported = set()
+    for node in ast.walk(tree):
+        if isinstance(node, ast.Import):
+            imported |= {a.name.split(".")[0] for a in node.names}
+        elif isinstance(node, ast.ImportFrom) and node.module:
+            imported.add(node.module.split(".")[0])
+    assert "subprocess" not in imported, (
+        "the mint script imports subprocess — a mint that can read history is "
+        "a commit-time deriver wearing the wrong name"
+    )
+
+    called = {ast.unparse(n.func) for n in ast.walk(tree) if isinstance(n, ast.Call)}
+    assert "datetime.now" in called, "the mint script no longer reads a clock"
+
+
+# ── The rewrite ────────────────────────────────────────────────────────────
+
+
+def test_the_rewrite_touches_exactly_one_line():
+    """Surgical, not a JSON round-trip. The manifest's formatting and key order
+    are not this script's to decide, and a whole-file reformat would make every
+    mint an unreadable diff."""
+    before = fake_manifest("0.1.48")
+    after = rewrite(before, "2026.09.01.2252")
+
+    b, a = before.splitlines(), after.splitlines()
+    assert len(b) == len(a)
+    differing = [i for i, (x, y) in enumerate(zip(b, a)) if x != y]
+    assert len(differing) == 1
+    assert '"version": "2026.09.01.2252"' in a[differing[0]]
+
+
+def test_the_rewrite_preserves_indentation_and_key_order():
+    weird = '{\n\t"name": "scribe",\n\t"version": "0.1.48",\n\t"z": 1\n}\n'
+    out = rewrite(weird, "2026.09.01.2252")
+    assert out == '{\n\t"name": "scribe",\n\t"version": "2026.09.01.2252",\n\t"z": 1\n}\n'
+
+
+def test_the_rewrite_refuses_a_manifest_it_cannot_match():
+    """Raises rather than falling back to a JSON round-trip: a manifest this
+    cannot match is one whose shape changed, and quietly reformatting the file
+    to cope would be a far larger edit than the caller asked for."""
+    with pytest.raises(ValueError):
+        rewrite('{"name": "scribe"}', "2026.09.01.2252")
+
+
+def test_the_rewrite_refuses_TWO_version_lines():
+    """A capped `subn` would report one replacement and look clean while the
+    second `version` — possibly the real one — kept its old value."""
+    two = '{\n  "version": "0.1.48",\n  "nested": {\n  "version": "9.9.9"\n  }\n}\n'
+    with pytest.raises(ValueError):
+        rewrite(two, "2026.09.01.2252")
+
+
+# ── The version-relevant set includes its own deriver ──────────────────────
+
+
+def test_the_mint_script_is_version_relevant():
+    """#3127 §3's asymmetry. A change to how the version is COMPUTED is
+    compared against nothing — leave the deriver out of the set and a format
+    change never forces a re-mint, so the manifest keeps a value in the old
+    format indefinitely and nothing says so."""
+    paths = check_plugin.version_relevant_paths()
+    assert "scripts/mint_plugin_version.py" in paths
+    for shipped in check_plugin.SHIPPED_PATHS:
+        assert shipped in paths
+
+
+def test_the_checker_is_NOT_version_relevant():
+    """The inverse, and it is the easy mistake. A checker decides whether the
+    lane goes red, not what the artifact reports — so its absence here is a
+    decision, not an oversight."""
+    assert "scripts/check_plugin.py" not in check_plugin.version_relevant_paths()
+
+
+# ── The check ──────────────────────────────────────────────────────────────
+
+
+def run_check(here: str, there: str | None, changed_paths: list[str], monkeypatch):
+    """Drive `check_version_is_minted` with git stubbed. Returns the failures."""
+    monkeypatch.setattr(
+        check_plugin, "_git",
+        lambda *a: (0, "\n".join(changed_paths)) if a[0] == "diff" else (0, ""),
+    )
+    monkeypatch.setattr(
+        check_plugin, "manifest_version",
+        lambda ref=None: here if ref is None else there,
+    )
+    monkeypatch.setattr(
+        check_plugin, "manifest_text",
+        lambda ref=None: fake_manifest(here if ref is None else (there or "0.0.0.0000")),
+    )
+    check_plugin.check_version_is_minted("origin/main")
+    return list(check_plugin.failures)
+
+
+def test_content_changed_and_the_version_did_not_FAILS(monkeypatch):
+    """#2209, exactly. The headline, and the only reason the check exists."""
+    failures = run_check(
+        "2026.09.01.2252", "2026.09.01.2252",
+        ["plugin/hooks/scribe_session_context.sh"], monkeypatch,
+    )
+    assert len(failures) == 1
+    assert "still 2026.09.01.2252" in failures[0]
+    assert "scribe_session_context.sh" in failures[0]
+
+
+def test_content_changed_and_the_version_moved_PASSES(monkeypatch):
+    assert run_check(
+        "2026.09.01.2252", "2026.08.30.1200",
+        ["plugin/hooks/scribe_session_context.sh"], monkeypatch,
+    ) == []
+
+
+def test_a_version_that_is_not_the_canonical_shape_FAILS(monkeypatch):
+    """`K4` returns the manifest string verbatim, so a malformed value is not
+    rejected by the installer — it either sorts as an ordinary string or, when
+    unreadable, forces a reinstall every session. Neither is loud (#3325)."""
+    failures = run_check("0.1.48", "0.1.47", [], monkeypatch)
+    assert len(failures) == 1
+    assert "not YYYY.MM.DD.HHMM" in failures[0]
+
+
+@pytest.mark.parametrize("bad", ["2026.9.1.2252", "2026.09.01.252", "2026.09.01"])
+def test_an_UNPADDED_or_short_version_FAILS(bad, monkeypatch):
+    """The padding is the contract, not cosmetics — one shape for every version
+    in the family (#3127 checklist 10)."""
+    assert run_check(bad, "2026.08.30.1200", [], monkeypatch) != []
+
+
+def test_a_version_in_the_future_FAILS(monkeypatch):
+    ahead = (datetime.now(timezone.utc) + timedelta(days=400)).strftime("%Y.%m.%d.%H%M")
+    failures = run_check(ahead, "2026.08.30.1200", [], monkeypatch)
+    assert len(failures) == 1
+    assert "in the future" in failures[0]
+
+
+def test_a_version_minted_minutes_ago_is_NOT_in_the_future(monkeypatch):
+    """The guard has to tolerate ordinary skew: the mint happens on a
+    workstation and the lane runs later, on another machine's clock."""
+    now = datetime.now(timezone.utc).strftime("%Y.%m.%d.%H%M")
+    assert run_check(now, "2026.08.30.1200", [], monkeypatch) == []
+
+
+def test_nothing_changed_and_nothing_minted_PASSES(monkeypatch):
+    assert run_check("2026.09.01.2252", "2026.09.01.2252", [], monkeypatch) == []
+
+
+def test_a_version_that_moved_with_no_content_change_is_NOT_a_failure(monkeypatch):
+    """Deliberately a pass. A needless re-mint costs one cache refresh; failing
+    the lane over a harmless act is how a check earns a `--no-version` in
+    somebody's muscle memory and stops running at all. The implication that
+    matters is one-directional: content changed IMPLIES version moved."""
+    assert run_check("2026.09.01.2252", "2026.08.30.1200", [], monkeypatch) == []
+
+
+def test_a_failed_diff_FAILS_rather_than_passing_quietly(monkeypatch):
+    """A check that cannot run must not report the same thing as a check that
+    passed — #2663's lesson, and the reason this file's siblings exist.
+
+    `rev-parse` is stubbed to SUCCEED so only the diff fails. Failing every git
+    call would trip the base-branch guard first and this would pass while
+    proving nothing about the diff arm.
+    """
+    monkeypatch.setattr(
+        check_plugin, "_git",
+        lambda *a: (128, "fatal: bad object") if a[0] == "diff" else (0, ""),
+    )
+    monkeypatch.setattr(check_plugin, "manifest_version",
+                        lambda ref=None: "2026.09.01.2252")
+    check_plugin.check_version_is_minted("origin/main")
+    assert len(check_plugin.failures) == 1
+    assert "git diff" in check_plugin.failures[0]
+
+
+# ── The real manifest ──────────────────────────────────────────────────────
+
+
+def test_the_shipped_manifest_carries_a_minted_version():
+    """The end of the hand-bumped scheme, asserted on the real file. `0.1.48`
+    was the last of 48 numbers a person typed."""
+    version = json.loads(check_plugin.MANIFEST.read_text())["version"]
+    assert VERSION_RE.match(version), (
+        f"the shipped manifest says {version!r}, which is not a minted version"
+    )
+
+
+def test_the_session_context_hook_still_reads_the_version_field():
+    """The marker #2220 asked for. The value's SHAPE changed, not the field or
+    its reader — if this had to move, the derivation went somewhere it should
+    not have."""
+    hook = (check_plugin.HOOKS_DIR / "scribe_session_context.sh").read_text()
+    assert re.search(r"jq\s+-r\s+'\.version", hook)

tests/test_routes_rulebooks.py

@@ -122,3 +122,27 @@ def test_rule_and_subscription_handlers_callable():
         "relate_rules", "unrelate_rules",
     ):
         assert callable(getattr(rb_routes, name))
+
+
+def test_the_rule_list_zero_fills_usage_on_every_row():
+    """Milestone 333 step 5, asserted the only way this harness allows.
+
+    There is no live-HTTP fixture here (see this module's docstring), so this
+    reads the handler's source. What it can still prove is the property that
+    gets forgotten: the route must attach the key to EVERY row, zero-filled,
+    rather than only to rows that happen to have events. Every rule on every
+    existing install predates `rule_usage_events`, so a route that only
+    attached the key when it found something would leave the badge component
+    reading `undefined` on almost every row — and the difference between "no
+    events" and "no field" is exactly the distinction #2663 is about.
+    """
+    import inspect
+
+    from scribe.routes import rulebooks as rb_routes
+
+    src = inspect.getsource(rb_routes.list_rules)
+    assert "usage_for_rules" in src, "the rule list does not read usage at all"
+    assert "empty_rule_usage()" in src, (
+        "the rule list does not zero-fill — a rule with no events would come "
+        "back without the key rather than with an empty one"
+    )

tests/test_rule_creation_asks_first.py

@@ -0,0 +1,120 @@
+"""Both rule-creation tools run the propose-then-approve loop (#3557).
+
+WHY THIS EXISTS
+
+Every other gate on `create_rule` and `create_project_rule` is about SHAPE:
+is this a rule or a process, is it one thing you could violate, is it general
+enough for a rulebook, is it a near-duplicate. All of those improve a rule
+someone has already decided to write. None of them asks the prior question —
+whether the person the rule will bind has agreed to be bound by it.
+
+That question belongs at the tool, because the tool is the last surface a
+caller reads before the write, and because the write is less reversible than
+it looks. The operator's yes is not merely consent; it is the one moment the
+rule is certainly IN FRONT of them. Afterwards it may not be again for
+months: a conditional rule is not read aloud at session start, and a
+project-scoped rule does not appear in an unfiltered `list_rules()` at all.
+The proposal IS the review, so there had better be one.
+
+WHY IT IS PHRASED AS A PRACTICE AND NOT A PROHIBITION
+
+The first cut of this guidance opened "NOT YOURS TO CALL UNPROMPTED." That is
+the wrong instrument, and the failure it invites is worse than the one it
+prevents: a caller reading a prohibition stops NOTICING rule-shaped things,
+rather than noticing them and asking. The wanted behaviour is more proposals,
+not fewer — spotting that something has hardened into a standing instruction
+is valuable work, and the only step that was ever missing came after it.
+
+So the docstrings describe what to DO: propose readily, state four things,
+close with a question the operator answers in one word. This test is written
+the same way — it asserts the parts of the loop are present, and has nothing
+to say about any wording that forbids.
+
+The fourth element — how the rule would be ENFORCED — is not ceremony. It is
+the part that sometimes dissolves the rule: a thing a test can assert should
+be that test, and a rule is what is left when nothing mechanical can hold it.
+A rulebook grows by default and shrinks only on purpose, so the question that
+prevents a rule earns more than any question that improves one's wording.
+
+WHAT THIS PINS, AND WHAT IT DOES NOT
+
+STRUCTURE, never wording — the same bargain the disambiguator guard (#3123)
+strikes next door. Each element matches a family of synonyms, so the prose
+stays free to be rewritten, reordered or sharpened; only DELETING one fails.
+Pinning phrasing would make every improvement a red build, and a test that
+punishes editing is a test someone deletes.
+
+It cannot tell whether an agent actually proposes. Nothing in a docstring
+can. It catches the regression that really happens: guidance tidied away in
+a later pass by someone who read it as throat-clearing in front of the Args.
+"""
+import pytest
+
+from tests.helpers import tool_doc as _doc
+
+# Both surfaces, because the one that needs it most is the one that looks
+# minor. A project rule is the least visible record the system can hold —
+# absent from an unfiltered list_rules(), and absent from session start too
+# whenever it is conditional — so the surface that writes one carries the
+# larger risk while reading as the smaller act.
+_SURFACES = [
+    ("scribe.mcp.tools.rulebooks", "create_rule"),
+    ("scribe.mcp.tools.rulebooks", "create_project_rule"),
+]
+
+# The loop, element by element, each as a family of ways to say it. A
+# docstring satisfies an element by containing ANY member — that is the room
+# left for rewriting. The families deliberately exclude bare words a
+# docstring would hold by accident ("why", "how", "reason", "rule"), which
+# would let the assertion pass on prose that says nothing of the kind.
+_ELEMENTS = {
+    "the invitation to propose": ("propose", "proposal"),
+    "the operator's approval": ("approve", "approval", "says yes", "a yes"),
+    "the rule's intent": ("intent", "what it changes about how work"),
+    "why it is being proposed now": (
+        "why now", "arose_from_id", "the incident", "prompted it",
+    ),
+    "how it would be enforced": ("enforc",),
+    "the answers offered back": ("as written", "talk about it", "discuss"),
+}
+
+
+@pytest.mark.parametrize(("module", "name"), _SURFACES)
+@pytest.mark.parametrize("element", sorted(_ELEMENTS))
+def test_a_rule_surface_carries_every_part_of_the_proposal_loop(
+    module, name, element
+):
+    """Each element of propose → state four things → ask survives."""
+    doc = _doc(module, name).lower()
+    assert any(token in doc for token in _ELEMENTS[element]), (
+        f"{name}'s docstring no longer mentions {element}. A caller reads "
+        f"this immediately before writing a rule that will bind every future "
+        f"session, and the proposal is the one moment that rule is certain to "
+        f"be seen by the operator. Say it in whatever words you like; this "
+        f"guard only checks it is still said. See create_rule's opening."
+    )
+
+
+@pytest.mark.parametrize(("module", "name"), _SURFACES)
+def test_the_proposal_loop_comes_before_the_parameter_contract(module, name):
+    """It has to be read to work, and the Args: block is where reading stops.
+
+    A caller who has decided to make the call skims down to the parameters.
+    Guidance parked below them — or folded into one argument's description —
+    arrives after the decision it was meant to inform, which is the same as
+    not being there.
+    """
+    doc = _doc(module, name).lower()
+    args_at = doc.find("args:")
+    assert args_at > 0, f"{name}'s docstring has no Args: block"
+    loop_at = min(
+        (doc.find(t) for t in _ELEMENTS["the invitation to propose"]
+         if doc.find(t) >= 0),
+        default=-1,
+    )
+    assert 0 <= loop_at < args_at, (
+        f"{name} introduces the proposal loop at or after its Args: block "
+        f"(loop {loop_at}, args {args_at}). Move it to the opening — a "
+        f"caller who has already decided to write the rule reads the "
+        f"parameters, not the prose under them."
+    )

tests/test_rule_usage_wiring.py

@@ -0,0 +1,868 @@
+"""Both ends of the rule-usage loop are actually wired (milestone 333 step 2).
+
+Step 1 built the table and the service. A counter nobody calls reads zero and
+looks exactly like a surface nobody uses — which is #2663's shape and the whole
+reason this milestone exists. So this file is about the CALL SITES, not the
+storage.
+
+Cross-cutting on purpose: the surfaced end lives in `plugin_context`, the pull
+end in two different doors, and the property under test is that they meet. Split
+across three module-shaped files, "both ends are wired" is a thing no single
+test asserts.
+"""
+from contextlib import ExitStack
+from pathlib import Path
+from unittest.mock import AsyncMock, MagicMock, patch
+
+import pytest
+
+from tests.helpers import fake_note, fake_rule
+
+# The MCP tool layer reads its caller from a ContextVar the HTTP transport sets
+# per request; a unit test has no request, so it binds the caller itself. The
+# arm tests do not need it — build_write_path_hint takes user_id directly — but
+# the module-level mark is how every tool-layer test file in this repo opts in.
+pytestmark = pytest.mark.usefixtures("_bind_user")
+
+
+# ── The surfaced end ───────────────────────────────────────────────────
+#
+# conftest's autouse `_no_rule_arm` stubs `semantic_search_rules` so unrelated
+# plugin-context tests don't pull a real embedding model through this arm. Its
+# docstring says a test that wants the arm live can re-patch it — that is what
+# each of these does.
+
+
+# The write-path hint returns early when a write matched nothing at all — no
+# staleness, no synced record, no prior-art menu, no shape signal. The rule arm
+# sits deliberately on the FAR side of that guard, because it runs a semantic
+# search and moving it above would mean an embedding query on every write in
+# the session (#3311's closing note, and the reason its gating is a separate
+# question from precision).
+#
+# So a fixture that stubs every other arm to empty never reaches the rule arm
+# at all — which is what the first run of this file did. The note hit below is
+# not decoration: it is the condition the arm requires in order to fire.
+_PRIOR_ART = [(0.72, fake_note(id=9, title="debounce helper", user_id=1,
+                               note_type="snippet"))]
+
+
+def _arm_patches(pc, hits, recorder, prior_art=None, cfg=None, rule_search=None,
+                 retrieval_log=None):
+    """The minimum stubbing that lets the rule arm run and nothing else.
+
+    `cfg`, `rule_search` and `retrieval_log` are overridable so a caller can
+    inspect what the arm ASKED for, and what it told the CALL log, rather than
+    only what it did with the answer — patching them a second time on top would
+    work, but reads as an accident.
+    """
+    return (
+        patch.object(pc, "get_writepath_config",
+                     AsyncMock(return_value=cfg or {
+                         "enabled": True, "threshold": 0.6,
+                         "top_k": 3, "rule_threshold": 0.6,
+                     })),
+        patch.object(pc.snippets_svc, "list_snippets", AsyncMock(return_value=([], 0))),
+        patch.object(pc, "semantic_search_notes",
+                     AsyncMock(return_value=_PRIOR_ART if prior_art is None
+                               else prior_art)),
+        patch.object(pc, "semantic_search_rules",
+                     rule_search or AsyncMock(return_value=hits)),
+        patch.object(pc, "record_retrieval", retrieval_log or MagicMock()),
+        patch.object(pc, "record_surfaced", MagicMock()),
+        patch.object(pc, "record_rule_surfaced", recorder),
+        patch.object(pc, "owner_names_for", AsyncMock(return_value={})),
+        patch.object(pc, "concept_query", MagicMock(return_value="a deadline on a fetch")),
+    )
+
+
+async def _run_arm(hits, recorder, prior_art=None, retrieval_log=None, **kwargs):
+    from scribe.services import plugin_context as pc
+    with ExitStack() as stack:
+        for ctx in _arm_patches(pc, hits, recorder, prior_art,
+                                retrieval_log=retrieval_log):
+            stack.enter_context(ctx)
+        return await pc.build_write_path_hint(
+            1, "frontend/src/api/client.ts", code="x" * 400, **kwargs
+        )
+
+
+@pytest.mark.asyncio
+async def test_the_arm_records_what_it_showed():
+    """The claim being measured. Without this call the arm keeps producing
+    scores in retrieval_logs and no evidence that any hint was ever read."""
+    rec = MagicMock()
+    hits = [(0.71, fake_rule(id=156, title="A wait with no deadline is a bug"))]
+    await _run_arm(hits, rec)
+
+    assert rec.call_count == 1
+    kw = rec.call_args.kwargs
+    assert kw["rule_ids"] == [156]
+    assert kw["source"] == "write_path_rule"
+
+
+@pytest.mark.asyncio
+async def test_a_rule_the_session_already_holds_is_not_counted_as_surfaced():
+    """`exclude_rule_ids` drops what the session already has, and the recorded
+    set must be what was SHOWN, not what was considered.
+
+    Counting the excluded ones would inflate the denominator with claims the
+    agent never saw — the ratio would fall for a reason that has nothing to do
+    with whether the hints landed, which is precisely the misreading this
+    milestone exists to prevent.
+    """
+    rec = MagicMock()
+    hits = [
+        (0.71, fake_rule(id=156, title="A wait with no deadline is a bug")),
+        (0.70, fake_rule(id=157, title="A loop re-arms in a finally")),
+    ]
+    await _run_arm(hits, rec, exclude_rule_ids=[157])
+
+    assert rec.call_args.kwargs["rule_ids"] == [156]
+
+
+@pytest.mark.asyncio
+async def test_nothing_is_recorded_when_every_hit_was_already_held():
+    """No surfacing happened, so no surfacing is recorded. A zero-row batch
+    would still be a call, and a call that says "we showed nothing" pollutes
+    the count of times the arm spoke."""
+    rec = MagicMock()
+    hits = [(0.71, fake_rule(id=156, title="A wait with no deadline is a bug"))]
+    await _run_arm(hits, rec, exclude_rule_ids=[156])
+
+    assert rec.call_count == 0
+
+
+@pytest.mark.asyncio
+async def test_the_arm_searches_on_its_OWN_bar_not_the_code_one():
+    """The consuming half of step 4. `get_writepath_config` assembling a
+    separate `rule_threshold` means nothing if the arm still passes
+    `cfg["threshold"]` to its search — the split would exist in the config and
+    not in the behaviour, and #3311 would be exactly where it was.
+
+    The two values are deliberately different here so the assertion can tell
+    them apart.
+    """
+    from scribe.services import plugin_context as pc
+
+    search = AsyncMock(return_value=[])
+    with ExitStack() as stack:
+        for ctx in _arm_patches(
+            pc, [], MagicMock(), rule_search=search,
+            cfg={"enabled": True, "threshold": 0.60,
+                 "top_k": 3, "rule_threshold": 0.81},
+        ):
+            stack.enter_context(ctx)
+        await pc.build_write_path_hint(
+            1, "frontend/src/api/client.ts", code="x" * 400,
+        )
+
+    kw = search.await_args.kwargs
+    assert kw["threshold"] == 0.81, "the arm is still using the code threshold"
+    assert kw["limit"] == pc.RULEHINT_LIMIT
+    # NO tier filter (#3702). The arms search every rule the caller owns,
+    # because "already in the session" is not the same as "in front of the
+    # reader at the moment it applies" — and relevance is the threshold's
+    # job, not a category's. If this assertion is failing because a tier
+    # argument came back, read the block above RULEHINT_LIMIT first: the
+    # filter may legitimately return, but only carrying a measured reason.
+    assert "tier" not in kw or kw["tier"] is None, (
+        "the arm is filtering the rule corpus by tier again"
+    )
+
+
+@pytest.mark.asyncio
+async def test_the_arm_does_not_fire_on_a_write_that_matched_nothing():
+    """The gate, pinned — because the fixture above now depends on it and a
+    silent change would make every other test here pass vacuously.
+
+    A write matching no prior art returns before the rule arm runs. That is
+    deliberate: the arm is a semantic search, and ungating it means an
+    embedding query on every write in the session. #3311 is explicit that the
+    gate stays until the arm's precision is fixed, so this failing is a signal
+    to go read that issue rather than to update the assertion.
+    """
+    rec = MagicMock()
+    hits = [(0.71, fake_rule(id=156, title="A wait with no deadline is a bug"))]
+    await _run_arm(hits, rec, prior_art=[])
+
+    assert rec.call_count == 0
+
+
+@pytest.mark.asyncio
+async def test_a_failing_recorder_does_not_break_the_write():
+    """Telemetry must never take down the surface it observes. The arm is
+    already wrapped in a fail-open try/except; this pins that the new call is
+    INSIDE it rather than after."""
+    rec = MagicMock(side_effect=RuntimeError("telemetry is down"))
+    hits = [(0.71, fake_rule(id=156, title="A wait with no deadline is a bug"))]
+    out = await _run_arm(hits, rec)
+
+    assert "context" in out
+
+
+# ── The pull end ───────────────────────────────────────────────────────
+
+
+@pytest.mark.asyncio
+async def test_mcp_get_rule_records_an_agent_pull():
+    """THE pull that matters: the arm's own message ends "Read it with
+    get_rule(N)", so this is the exact action a landed hint produces."""
+    rec = MagicMock()
+    rule = fake_rule(id=156, title="A wait with no deadline is a bug")
+    with patch("scribe.mcp.tools.rulebooks.rulebooks_svc.get_rule",
+               AsyncMock(return_value=rule)), \
+         patch("scribe.mcp.tools.rulebooks.rulebooks_svc.rule_detail",
+               AsyncMock(return_value={"id": 156})), \
+         patch("scribe.mcp.tools.rulebooks.record_rule_pulled", rec):
+        from scribe.mcp.tools.rulebooks import get_rule
+        await get_rule(rule_id=156)
+
+    assert rec.call_args.kwargs["rule_id"] == 156
+    assert rec.call_args.kwargs["source"] == "mcp_get_rule"
+
+
+@pytest.mark.asyncio
+async def test_a_rule_that_cannot_be_read_is_not_a_pull():
+    """Recorded after the access check. A refused read is not a pull, and
+    counting it would credit the arm for a hint nobody could open."""
+    rec = MagicMock()
+    with patch("scribe.mcp.tools.rulebooks.rulebooks_svc.get_rule",
+               AsyncMock(return_value=None)), \
+         patch("scribe.mcp.tools.rulebooks.record_rule_pulled", rec):
+        from scribe.mcp.tools.rulebooks import get_rule
+        with pytest.raises(ValueError):
+            await get_rule(rule_id=156)
+
+    assert rec.call_count == 0
+
+
+# ── Completeness: every door, and only the doors ───────────────────────
+
+
+def _source_of(module_path: str) -> str:
+    return (Path(__file__).resolve().parents[1] / module_path).read_text()
+
+
+def test_every_rule_detail_door_records_a_pull():
+    """The task's own warning, made mechanical: miss a door and the ratio
+    reads low for a reason that is not about the rules.
+
+    Source inspection rather than behaviour, because the REST door has no
+    live-HTTP harness in the unit lane (see test_routes_rulebooks.py's own
+    note). What it can still prove is that the handler names the recorder —
+    which is the thing that gets forgotten when a door is added.
+    """
+    rest = _source_of("src/scribe/routes/rulebooks.py")
+    mcp = _source_of("src/scribe/mcp/tools/rulebooks.py")
+    assert 'source="rest_rule"' in rest, (
+        "the REST rule-detail route does not record a pull"
+    )
+    assert 'source="mcp_get_rule"' in mcp, (
+        "the MCP get_rule tool does not record a pull"
+    )
+
+
+def test_the_bulk_loaders_are_not_counted_as_pulls():
+    """`list_always_on_rules` and `enter_project` hand over every applicable
+    rule at once. That is delivery, not somebody choosing to open one record,
+    and counting it would swamp the signal with exactly the ambient surfacing
+    the ratio exists to distinguish from.
+
+    Stated as a test because it is the tempting addition: both put rules in
+    front of an agent, so "surely those are pulls too" is the reading someone
+    arrives at without the argument.
+    """
+    for path in ("src/scribe/mcp/tools/rulebooks.py",
+                 "src/scribe/mcp/tools/projects.py"):
+        src = _source_of(path)
+        for door in ("list_always_on_rules", "enter_project"):
+            if f"async def {door}" not in src:
+                continue
+            body = src.split(f"async def {door}", 1)[1].split("\nasync def ", 1)[0]
+            assert "record_rule_pulled" not in body, (
+                f"{door} records a pull. It is a bulk resident load — every "
+                "applicable rule at once — so counting it would drown the "
+                "surfaced:pulled ratio in ambient delivery."
+            )
+
+
+# ── The AMBIENT end: bulk deliveries (#3473) ───────────────────────────
+#
+# The preload was the largest rule surface in the product and emitted nothing,
+# so its cost was certain and its usefulness unfalsifiable. These assert the
+# three delivery shapes now emit — and, just as importantly, that the two
+# lookalike call sites which show nobody anything do NOT.
+
+
+@pytest.mark.asyncio
+async def test_the_session_start_preload_records_what_it_delivered():
+    """The block every session opens with. Chosen by nobody, paid for every
+    turn — and until it emitted, invisible to the scoreboard that judges every
+    other surface."""
+    from scribe.services import plugin_context as pc
+
+    rec = MagicMock()
+    rules = [fake_rule(id=1, title="`dev` is home"),
+             fake_rule(id=2, title="`main` — never without explicit request")]
+    with ExitStack() as stack:
+        stack.enter_context(
+            patch.object(pc.rulebooks_svc, "list_always_on_rules",
+                         AsyncMock(return_value=rules))
+        )
+        stack.enter_context(
+            patch.object(pc.rulebooks_svc, "excluded_always_on_rulebooks",
+                         AsyncMock(return_value=[]))
+        )
+        stack.enter_context(patch.object(pc, "record_rule_surfaced", rec))
+        stack.enter_context(
+            patch.object(pc, "_topic_titles", AsyncMock(return_value={}))
+        )
+        await pc.build_session_context(1, project_id=0)
+
+    assert rec.call_count == 1, "the preload recorded nothing"
+    kw = rec.call_args.kwargs
+    assert kw["rule_ids"] == [1, 2]
+    assert kw["source"] == "session_start"
+
+
+@pytest.mark.asyncio
+async def test_the_always_on_tool_records_what_it_handed_over():
+    from scribe.mcp.tools import rulebooks as tools
+
+    rec = MagicMock()
+    rules = [fake_rule(id=3, title="No GitHub — Fabled-Git only")]
+    with ExitStack() as stack:
+        stack.enter_context(
+            patch.object(tools.rulebooks_svc, "list_always_on_rules",
+                         AsyncMock(return_value=rules))
+        )
+        stack.enter_context(
+            patch.object(tools.rulebooks_svc, "rules_etag",
+                         MagicMock(return_value="etag"))
+        )
+        stack.enter_context(patch.object(tools, "record_rule_surfaced", rec))
+        await tools.list_always_on_rules()
+
+    assert rec.call_args.kwargs["rule_ids"] == [3]
+    assert rec.call_args.kwargs["source"] == "list_always_on_rules"
+
+
+def test_rules_payload_records_both_the_family_and_project_halves():
+    """One emit site for all five `rules_payload` surfaces.
+
+    Per-caller emission would be five sites to remember, and #3430 gap 2 is
+    what that costs: the process→skill sync went un-emitted through an entire
+    dedicated telemetry survey because nothing forced its surface to be
+    accounted for.
+    """
+    from scribe.services import rulebooks as svc
+
+    rec = MagicMock()
+    with patch.object(svc, "record_rule_surfaced", rec):
+        svc.rules_payload(
+            {
+                "rules": [{"id": 10}, {"id": 11}],
+                "project_rules": [{"id": 12}],
+                "truncated": False,
+                "subscribed_rulebooks": [],
+            },
+            user_id=1,
+            source="enter_project",
+        )
+
+    kw = rec.call_args.kwargs
+    assert kw["rule_ids"] == [10, 11, 12], "project-scoped rules were delivered too"
+    assert kw["source"] == "enter_project"
+
+
+def test_every_rules_payload_caller_names_itself():
+    """`source` is the CALLER's name, so the readout can still separate the
+    session handshake from a mid-session milestone read. A shared constant here
+    would collapse five distinguishable surfaces into one."""
+    import re
+
+    seen = set()
+    for path in Path("src/scribe").rglob("*.py"):
+        for m in re.finditer(r"rules_payload\([^)]*source=\"([a-z_]+)\"", path.read_text()):
+            seen.add(m.group(1))
+    assert seen == {
+        "enter_project", "get_project", "get_milestone",
+        "start_planning", "get_task",
+    }, f"a rules_payload caller is missing or misnamed: {sorted(seen)}"
+
+
+def test_the_marker_paths_stay_silent():
+    """The two call sites that read the rules and show NOBODY anything.
+
+    `rules_etag_for` and the write-path staleness arm both call
+    `list_always_on_rules` to build or compare a marker. Emitting there would
+    put rules in the denominator that no agent ever saw — the exact inflation
+    `record_rule_surfaced`'s docstring forbids, arriving from the one direction
+    nothing else guards.
+    """
+    svc_src = Path("src/scribe/services/rulebooks.py").read_text()
+    etag_fn = svc_src.split("async def rules_etag_for")[1].split("\ndef ")[0]
+    assert "record_rule_surfaced" not in etag_fn, (
+        "rules_etag_for emits a surfacing — it builds a marker, it shows nothing"
+    )
+
+    pc_src = Path("src/scribe/services/plugin_context.py").read_text()
+    staleness = pc_src.split("if rules_etag:")[1].split("# The guard sits BELOW")[0]
+    assert "record_rule_surfaced" not in staleness, (
+        "the staleness arm emits a surfacing — it compares a marker, it shows nothing"
+    )
+
+
+# ── The PRE-TOOL arm: rules keyed on the action (#3476) ────────────────
+#
+# The write-path arm can only be reached by a code write, so every rule about
+# which tool to reach for was unretrievable at the moment it mattered — which
+# is why they all had to be resident. These cover the surface that changes it.
+
+
+def _tool_patches(pc, hits, recorder, cfg=None, retrieval_log=None):
+    return (
+        patch.object(pc, "get_writepath_config",
+                     AsyncMock(return_value=cfg or {
+                         "enabled": True, "threshold": 0.6,
+                         "top_k": 3, "rule_threshold": 0.6,
+                     })),
+        patch.object(pc, "semantic_search_rules", AsyncMock(return_value=hits)),
+        patch.object(pc, "record_retrieval", retrieval_log or MagicMock()),
+        patch.object(pc, "record_rule_surfaced", recorder),
+    )
+
+
+async def _run_tool_arm(hits, recorder, command="curl -s https://git.example/api/v1/runs",
+                        tool="Bash", retrieval_log=None, **kwargs):
+    from scribe.services import plugin_context as pc
+    with ExitStack() as stack:
+        for ctx in _tool_patches(pc, hits, recorder, retrieval_log=retrieval_log):
+            stack.enter_context(ctx)
+        return await pc.build_tool_rule_hint(1, tool, command, **kwargs)
+
+
+@pytest.mark.asyncio
+async def test_the_tool_arm_names_a_rule_for_the_command_about_to_run():
+    """The 2026-09-03 incident in one test: reaching for curl against the forge
+    API is a Bash call, and nothing watched Bash."""
+    rec = MagicMock()
+    hits = [(0.71, fake_rule(id=161,
+                             title="Reach the forge through its MCP tools, never curl",
+                             when_to_apply="whenever you need CI status"))]
+    out = await _run_tool_arm(hits, rec)
+
+    assert out["rule_ids"] == [161]
+    assert "Reach the forge through its MCP tools" in out["context"]
+    assert "get_rule(161)" in out["context"], "the hint must hand over the way to read it"
+    assert "Bash" in out["context"], "the hint names the tool it is about"
+    assert rec.call_args.kwargs["source"] == "pre_tool_rule"
+
+
+@pytest.mark.asyncio
+async def test_the_tool_arm_is_a_ranked_source():
+    """It CHOSE what it showed, so a pull can settle whether the choice was any
+    good — unlike a preload, which chose nothing. If this drifts into the
+    ambient class the arm becomes unjudgeable, which is the state #3311
+    described and M333 existed to end."""
+    from scribe.services.rule_usage import is_ambient
+
+    assert not is_ambient("pre_tool_rule")
+
+
+@pytest.mark.asyncio
+async def test_a_rule_the_session_already_holds_is_not_re_offered():
+    rec = MagicMock()
+    hits = [(0.71, fake_rule(id=161, title="Reach the forge through its MCP tools")),
+            (0.70, fake_rule(id=12, title="Don't run a local stack unless asked"))]
+    out = await _run_tool_arm(hits, rec, exclude_rule_ids=[161])
+
+    assert out["rule_ids"] == [12]
+    assert "161" not in out["context"]
+
+
+@pytest.mark.asyncio
+async def test_an_empty_command_asks_the_ranker_nothing():
+    """Every Bash call reaches this. A blank payload must cost no embedding
+    query at all, not merely return nothing after paying for one."""
+    from scribe.services import plugin_context as pc
+
+    search = AsyncMock(return_value=[])
+    rec = MagicMock()
+    with ExitStack() as stack:
+        stack.enter_context(patch.object(pc, "semantic_search_rules", search))
+        stack.enter_context(patch.object(pc, "record_rule_surfaced", rec))
+        out = await pc.build_tool_rule_hint(1, "Bash", "   ")
+
+    assert out == {"context": "", "rule_ids": []}
+    search.assert_not_called()
+    rec.assert_not_called()
+
+
+@pytest.mark.asyncio
+async def test_the_tool_arm_fails_open():
+    """A recall aid may never break the operator's action. A ranker that raises
+    must cost the hint, not the command."""
+    from scribe.services import plugin_context as pc
+
+    with ExitStack() as stack:
+        stack.enter_context(patch.object(pc, "get_writepath_config",
+                                         AsyncMock(side_effect=RuntimeError("boom"))))
+        out = await pc.build_tool_rule_hint(1, "Bash", "docker compose up -d")
+
+    assert out == {"context": "", "rule_ids": []}
+
+
+@pytest.mark.asyncio
+async def test_a_long_command_is_bounded_before_it_reaches_the_ranker():
+    """A heredoc or a pasted script would push the verb and its target — the
+    part a rule is about — out of the embedding window."""
+    from scribe.services import plugin_context as pc
+
+    search = AsyncMock(return_value=[])
+    with ExitStack() as stack:
+        for ctx in _tool_patches(pc, [], MagicMock()):
+            stack.enter_context(ctx)
+        stack.enter_context(patch.object(pc, "semantic_search_rules", search))
+        await pc.build_tool_rule_hint(1, "Bash", "git tag v1 && " + "x" * 5000)
+
+    sent = search.call_args.args[1]
+    assert len(sent) <= pc._TOOL_QUERY_CHARS
+    assert sent.startswith("git tag v1"), "the head of the command is the signal"
+
+
+def test_the_two_pre_tool_arms_share_one_session_rule_ledger():
+    """The integration point most worth guarding.
+
+    Two ledgers would mean a rule named by the write arm gets re-offered by the
+    tool arm — and the hint that fires most often is exactly the one that must
+    not repeat itself. Asserted on the FILENAME both scripts build, because
+    that is the shared thing; a copy of the path in each is how they drift.
+    """
+    prior = Path("plugin/hooks/scribe_prior_art.sh").read_text()
+    tool = Path("plugin/hooks/scribe_tool_rules.sh").read_text()
+
+    for src, name in ((prior, "scribe_prior_art.sh"), (tool, "scribe_tool_rules.sh")):
+        assert '"${TMPDIR:-/tmp}/scribe-priorart"' in src, f"{name}: state dir moved"
+        assert '.rules.ids' in src, f"{name}: rules ledger filename moved"
+        assert "exclude_rule_ids" in src, f"{name}: does not send the exclusion"
+
+
+def test_the_tool_arm_is_registered_on_bash():
+    """A hook that exists and is not registered runs never — and reads exactly
+    like a surface nobody needed."""
+    import json
+
+    manifest = json.loads(Path("plugin/hooks/hooks.json").read_text())
+    pre = manifest["hooks"]["PreToolUse"]
+    entries = {
+        m.get("matcher"): [h["command"] for h in m["hooks"]] for m in pre
+    }
+    assert "Bash" in entries, "nothing watches Bash — the reflex surface is unguarded"
+    assert any("scribe_tool_rules.sh" in c for c in entries["Bash"])
+    # The write arm keeps its own matcher; this is an addition, not a move.
+    assert any("scribe_prior_art.sh" in c for c in entries["Write|Edit"])
+
+
+def test_the_hook_and_the_route_agree_on_every_parameter_name():
+    """Rule 33, on a brand-new integration between layers.
+
+    The hook is shell and the route is Python; nothing but this test connects
+    them. A renamed query arg fails SILENTLY — the route reads an absent value,
+    the arm quietly searches nothing, and the surface looks like one that never
+    finds anything rather than one that is broken.
+    """
+    import re
+
+    hook = Path("plugin/hooks/scribe_tool_rules.sh").read_text()
+    route = Path("src/scribe/routes/plugin.py").read_text()
+    handler = route.split("async def pre_tool_rules")[1].split("\n@plugin_bp")[0]
+
+    sent = set(re.findall(r"[?&]([a-z_]+)=", hook))
+    assert sent == {"tool", "command", "repo", "exclude_rule_ids"}, sent
+
+    # `repo` is read by the shared _project_scope() helper, not inline.
+    assert "_project_scope()" in handler
+    for arg in ("tool", "command", "exclude_rule_ids"):
+        assert f'request.args.get("{arg}")' in handler, (
+            f"the hook sends {arg!r} and the route never reads it"
+        )
+
+
+# ── The CALL log is unconditional; the SURFACING log is not (#3497) ────
+#
+# Both arms used to write their retrieval_logs row inside a guard on having
+# results, so `zero_result_calls` was pinned at 0 and `cleared_threshold` at
+# `calls` by the shape of the code — at any threshold whatsoever. #3311 read
+# that as a measurement of the corpus and a milestone was scoped on it.
+#
+# The distinction these tests hold: a CALL happened whether or not it found
+# anything, and the calls that found nothing are the only evidence a threshold
+# is set too high. A SURFACING did not happen when nothing was shown.
+
+
+@pytest.mark.asyncio
+async def test_the_write_path_arm_logs_the_call_that_found_nothing():
+    log, rec = MagicMock(), MagicMock()
+    await _run_arm([], rec, retrieval_log=log)
+
+    rule_calls = [c for c in log.call_args_list
+                  if c.kwargs.get("source") == "write_path_rule"]
+    assert len(rule_calls) == 1, (
+        "a rule call that found nothing wrote no row — `zero_result_calls` can "
+        "then only ever read 0, however badly the threshold is tuned"
+    )
+    assert rule_calls[0].kwargs["results"] == []
+    rec.assert_not_called()
+
+
+@pytest.mark.asyncio
+async def test_the_write_path_arm_logs_a_call_whose_only_hit_was_already_shown():
+    """The subtler half. The ranker DID find something; the session had already
+    been told. That is a decline from the reader's side and must be logged as
+    one — the note arms get this for free by passing exclusions into the search,
+    so their zero-result rows already include this case."""
+    log, rec = MagicMock(), MagicMock()
+    hits = [(0.71, fake_rule(id=156, title="A wait with no deadline is a bug"))]
+    await _run_arm(hits, rec, retrieval_log=log, exclude_rule_ids=[156])
+
+    rule_calls = [c for c in log.call_args_list
+                  if c.kwargs.get("source") == "write_path_rule"]
+    assert len(rule_calls) == 1
+    assert rule_calls[0].kwargs["results"] == [], (
+        "the row must record what the arm could SHOW, so this row is comparable "
+        "with an auto_inject row, whose exclusions are applied by the search"
+    )
+    rec.assert_not_called()
+
+
+@pytest.mark.asyncio
+async def test_the_tool_arm_logs_the_call_that_found_nothing():
+    """It matters more here than on the sibling. This arm fires on every Bash
+    call, so an empty `sources` row is the normal outcome — and with no row at
+    all, "the ranker declined" is indistinguishable from "the hook never fired",
+    which is exactly the silent failure the arm was built to stop (#3476)."""
+    log, rec = MagicMock(), MagicMock()
+    out = await _run_tool_arm([], rec, retrieval_log=log)
+
+    assert out == {"context": "", "rule_ids": []}
+    assert log.call_count == 1
+    assert log.call_args.kwargs["source"] == "pre_tool_rule"
+    assert log.call_args.kwargs["results"] == []
+    assert log.call_args.kwargs["query"] == "curl -s https://git.example/api/v1/runs", (
+        "the query is the point of the row: it is what a threshold is tuned against"
+    )
+    rec.assert_not_called()
+
+
+@pytest.mark.asyncio
+async def test_the_tool_arm_logs_a_call_whose_only_hit_was_already_shown():
+    log, rec = MagicMock(), MagicMock()
+    hits = [(0.71, fake_rule(id=161, title="Reach the forge through its MCP tools"))]
+    out = await _run_tool_arm(hits, rec, retrieval_log=log, exclude_rule_ids=[161])
+
+    assert out["rule_ids"] == []
+    assert log.call_count == 1
+    assert log.call_args.kwargs["results"] == []
+    rec.assert_not_called()
+
+
+@pytest.mark.asyncio
+async def test_a_command_the_arm_never_searched_writes_no_row_at_all():
+    """The one case that must stay silent, and the boundary of the rule above.
+
+    A blank command costs no embedding query, so there was no retrieval to log.
+    A row here would report a call that never happened and drag the clear-rate
+    down with phantom declines — the mirror of the defect, from the other side.
+    """
+    from scribe.services import plugin_context as pc
+
+    log = MagicMock()
+    with ExitStack() as stack:
+        for ctx in _tool_patches(pc, [], MagicMock(), retrieval_log=log):
+            stack.enter_context(ctx)
+        await pc.build_tool_rule_hint(1, "Bash", "   ")
+
+    log.assert_not_called()
+
+
+def test_neither_rule_arm_logs_its_call_behind_a_results_guard():
+    """Structural, on top of the behavioural pair above, because the defect was
+    one level of indentation and it appeared INDEPENDENTLY in two places — the
+    pre-tool arm inherited it by being modelled on its sibling. The third arm
+    modelled on either of them is the one this catches.
+    """
+    pc_src = Path("src/scribe/services/plugin_context.py").read_text()
+
+    # Write-path arm: what remains inside `if fresh:` is the SURFACING log only.
+    guarded = pc_src.split('source="write_path_rule", query=code or path')[1]
+    guarded = guarded.split("if fresh:")[1].split("except Exception:")[0]
+    assert "record_rule_surfaced" in guarded, "the surfacing log must stay guarded"
+    assert "record_retrieval" not in guarded, (
+        "the call log is back inside the results guard — a call that found "
+        "nothing is the only evidence a threshold is set too high"
+    )
+
+    # Pre-tool arm: the call log comes BEFORE the early return.
+    body = pc_src.split("async def build_tool_rule_hint")[1]
+    assert body.index('source="pre_tool_rule"') < body.index("if not fresh:"), (
+        "the pre-tool arm returns before logging its call — a surface with no "
+        "rows at all cannot be told apart from a hook that never fired"
+    )
+
+
+# ── Suppression: which zeros were the ranker, which were repeats (#3497) ──
+#
+# Making the call log unconditional exposed a second ambiguity in the same row.
+# A zero-result rule call is two unrelated events: the ranker found nothing
+# above the bar, or it found only what this session already held. Only the
+# first says anything about the threshold, and a long session excludes its way
+# into the second — so without the split, the arm looks worse the longer it
+# runs correctly.
+
+
+@pytest.mark.asyncio
+async def test_the_write_path_arm_reports_what_the_session_already_held():
+    log, rec = MagicMock(), MagicMock()
+    hits = [(0.71, fake_rule(id=156, title="A wait with no deadline is a bug")),
+            (0.70, fake_rule(id=157, title="A loop re-arms in a finally"))]
+    await _run_arm(hits, rec, retrieval_log=log, exclude_rule_ids=[156, 157])
+
+    row = next(c for c in log.call_args_list
+               if c.kwargs.get("source") == "write_path_rule")
+    assert row.kwargs["results"] == []
+    assert row.kwargs["suppressed"] == 2, (
+        "both hits were repeats, so this zero is not evidence about the bar"
+    )
+
+
+@pytest.mark.asyncio
+async def test_a_genuine_ranker_decline_reports_zero_suppression():
+    """Zero, not None. The arm filters in Python, so it always knows — and
+    'measured none' has to stay distinguishable from 'cannot measure'."""
+    log, rec = MagicMock(), MagicMock()
+    await _run_arm([], rec, retrieval_log=log)
+
+    row = next(c for c in log.call_args_list
+               if c.kwargs.get("source") == "write_path_rule")
+    assert row.kwargs["suppressed"] == 0
+    assert row.kwargs["suppressed"] is not None
+
+
+@pytest.mark.asyncio
+async def test_the_tool_arm_reports_suppression_too():
+    log, rec = MagicMock(), MagicMock()
+    hits = [(0.75, fake_rule(id=161, title="Reach the forge through its MCP tools"))]
+    await _run_tool_arm(hits, rec, retrieval_log=log, exclude_rule_ids=[161])
+
+    assert log.call_args.kwargs["results"] == []
+    assert log.call_args.kwargs["suppressed"] == 1
+
+
+@pytest.mark.asyncio
+async def test_a_shown_hit_is_not_counted_as_suppressed():
+    """The obvious inverse, worth pinning: `suppressed` counts what was DROPPED,
+    not what came back. Off by one here and every zero row reads as a repeat."""
+    log, rec = MagicMock(), MagicMock()
+    hits = [(0.75, fake_rule(id=161, title="Reach the forge through its MCP tools")),
+            (0.70, fake_rule(id=12, title="Don't run a local stack unless asked"))]
+    out = await _run_tool_arm(hits, rec, retrieval_log=log, exclude_rule_ids=[12])
+
+    assert out["rule_ids"] == [161]
+    assert log.call_args.kwargs["suppressed"] == 1
+    assert len(log.call_args.kwargs["results"]) == 1
+
+
+# ── The identity that falsified this milestone (#3668) ─────────────────
+#
+# `rule_usage.surfaced` == `pre_tool_rule.cleared` + `write_path_rule.cleared`.
+# Milestone #379 was scoped on a reconstruction that put ~64% of ranked rule
+# surfacings as never reaching `rule_usage_events`. Five steps were planned
+# against it. One read of this identity — 17 = 17, then 39 = 39 on a second
+# window — falsified the whole thing: the gap was two counters that started
+# recording on different days, not a write path dropping rows.
+#
+# So the identity is not a nice-to-have. It is the cheapest true statement
+# available about this pair of tables, and its absence is what let a magnitude
+# that merely LOOKED wrong survive a code review and a five-step plan. An
+# identity that must hold exactly beats a magnitude that looks wrong.
+#
+# WHY THE ARM IS THE RIGHT PLACE TO PIN IT, and the readout is not. Inside an
+# arm, one `fresh` list feeds both recorders in one function, so the counts
+# cannot legitimately differ — at any limit. The readout-level form is weaker
+# than it looks: `cleared_threshold` counts CALLS that beat the bar while
+# `surfaced` counts RULES, and those coincide only while `RULEHINT_LIMIT` is 1.
+# Raise the limit and the readout identity breaks while nothing is wrong.
+# `RULEHINT_LIMIT` has already moved once (2 → 1, `2385100`), and that move is
+# half of why the original reconstruction misread its own numbers.
+#
+# Hence three hits below, where production currently returns at most one. The
+# test is deliberately in a state the limit does not permit today, because what
+# is being pinned is that the two recorders read the same list — not that the
+# list happens to be short.
+
+_THREE_HITS = [
+    (0.81, fake_rule(id=156, title="A wait with no deadline is a bug")),
+    (0.77, fake_rule(id=157, title="A loop re-arms in a finally")),
+    (0.74, fake_rule(id=161, title="Reach the forge through its MCP tools")),
+]
+
+_ARMS = [("write_path_rule", _run_arm), ("pre_tool_rule", _run_tool_arm)]
+
+
+def _both_ends(log, rec, source):
+    """What the two recorders said about one call, at the same grain.
+
+    Ids rather than counts. Equal counts drawn from different lists is a real
+    way for this to break — an off-by-one slice, or one recorder reading `hits`
+    where the other reads `fresh` in a window where the exclusion happened to
+    remove as many as it added — and a count comparison would call that agreement.
+    """
+    rows = [c for c in log.call_args_list if c.kwargs.get("source") == source]
+    assert len(rows) == 1, (
+        f"expected exactly one {source} call row, got {len(rows)} — the "
+        f"identity is per call and cannot be read across several"
+    )
+    logged = [rule.id for _score, rule in rows[0].kwargs["results"]]
+    surfaced = [
+        rid
+        for c in rec.call_args_list if c.kwargs.get("source") == source
+        for rid in c.kwargs["rule_ids"]
+    ]
+    return logged, surfaced
+
+
+@pytest.mark.parametrize(("source", "run"), _ARMS, ids=["write_path", "pre_tool"])
+@pytest.mark.parametrize(
+    ("excluded", "expected"),
+    [([], 3), ([157], 2), ([156, 157, 161], 0)],
+    ids=["nothing-held", "one-already-held", "all-already-held"],
+)
+@pytest.mark.asyncio
+async def test_both_recorders_report_the_same_rules_for_one_call(
+    source, run, excluded, expected
+):
+    """One list, two tables, no room to disagree.
+
+    The middle case is the one that discriminates. With nothing excluded both
+    recorders see the same three rules however wrongly they are wired, so an
+    arm logging `hits` to the call log and `fresh` to the surfacing log passes
+    that case and fails this one — and logging `hits` is exactly the divergence
+    that would manufacture an apparent write loss out of a correct system.
+    """
+    log, rec = MagicMock(), MagicMock()
+    await run(list(_THREE_HITS), rec, retrieval_log=log, exclude_rule_ids=excluded)
+
+    logged, surfaced = _both_ends(log, rec, source)
+    assert surfaced == logged, (
+        f"{source} told its two tables different stories about one call: the "
+        f"call log recorded {logged} and the surfacing log recorded {surfaced}. "
+        f"Both come from `fresh`, in one function, so any difference is a bug "
+        f"in the wiring — and it is the shape that reads as a lost write when "
+        f"the two tables are later compared in aggregate (#3668)."
+    )
+    assert len(logged) == expected, (
+        "the fixture stopped exercising what it claims to; check the exclusion "
+        "filter still runs before both recorders"
+    )

tests/test_services_backup.py

@@ -23,7 +23,7 @@ def test_backup_version_is_current():
 
     (Named for the number it asserted until v10, which is exactly the drift a
     name-carrying-a-value invites; it now says what it checks.)"""
-    assert backup.BACKUP_VERSION == 13
+    assert backup.BACKUP_VERSION == 14
 
 
 def _exportable_note(**over):
@@ -133,6 +133,7 @@ def _column_guard_targets():
     from scribe.models.note_draft import NoteDraft
     from scribe.models.note_supersession import NoteSupersession
     from scribe.models.note_usage import NoteUsageEvent
+    from scribe.models.rule_usage import RuleUsageEvent
     from scribe.models.note_version import NoteVersion
     from scribe.models.rule_version import RuleVersion
     from scribe.models.project import Project
@@ -162,6 +163,7 @@ def _column_guard_targets():
         "note_supersessions": (NoteSupersession, backup._note_supersession_rows),
         "rule_relations": (RuleRelation, backup._rule_relation_rows),
         "note_usage_events": (NoteUsageEvent, backup._usage_event_rows),
+        "rule_usage_events": (RuleUsageEvent, backup._rule_usage_event_rows),
         "design_systems": (DesignSystem, backup._design_system_rows),
         "design_tokens": (DesignToken, backup._design_token_rows),
         "repo_bindings": (RepoBinding, backup._repo_binding_rows),

tests/test_services_plugin_context.py

@@ -419,7 +419,8 @@ async def test_write_path_semantic_arm_asks_for_experience_not_just_snippets():
     rec = MagicMock()
     with patch.object(pc, "get_writepath_config",
                       AsyncMock(return_value={"enabled": True, "threshold": 0.6,
-                                              "top_k": 3})), \
+                                              "top_k": 3,
+                                              "rule_threshold": 0.72})), \
          patch.object(pc.snippets_svc, "list_snippets",
                       AsyncMock(return_value=([], 0))), \
          patch.object(pc, "semantic_search_notes", search), \
@@ -451,7 +452,8 @@ async def test_write_path_labels_a_non_snippet_hit_with_its_kind():
             (0.71, fake_note(id=7, title="Debounce dropped the trailing call", user_id=1, is_task=True, task_kind="issue"))]
     with patch.object(pc, "get_writepath_config",
                       AsyncMock(return_value={"enabled": True, "threshold": 0.6,
-                                              "top_k": 3})), \
+                                              "top_k": 3,
+                                              "rule_threshold": 0.72})), \
          patch.object(pc.snippets_svc, "list_snippets",
                       AsyncMock(return_value=([], 0))), \
          patch.object(pc, "semantic_search_notes", AsyncMock(return_value=hits)), \

tests/test_services_retrieval_telemetry.py

@@ -57,6 +57,68 @@ def test_build_payload_rounds_scores_to_5dp():
     assert p["result_ids"][0]["score"] == 0.12346
 
 
+# ─── suppression: "not measured" is not "none" (#3497) ───────────────────────
+
+
+def test_a_caller_that_cannot_measure_suppression_stores_null():
+    """The distinction the whole column exists for.
+
+    A surface that passes its exclusions into the search never sees what was
+    dropped. Storing 0 would assert a clean run nobody observed — reading an
+    artifact as a measurement, which is exactly #3311's mistake.
+    """
+    p = _build_payload(
+        user_id=1, source="auto_inject", query="q", threshold=0.6,
+        limit=3, project_id=None, is_task=None, results=[], duration_ms=None,
+    )
+    assert p["suppressed_count"] is None, "unmeasured must not render as zero"
+
+
+def test_a_caller_that_measured_no_suppression_stores_zero():
+    """The other side of it. Zero is a real observation and must survive."""
+    p = _build_payload(
+        user_id=1, source="pre_tool_rule", query="git status", threshold=0.6,
+        limit=1, project_id=None, is_task=None, results=[], duration_ms=None,
+        suppressed=0,
+    )
+    assert p["suppressed_count"] == 0
+
+
+def test_the_count_of_hits_the_reader_already_held_is_carried():
+    p = _build_payload(
+        user_id=1, source="write_path_rule", query="code", threshold=0.6,
+        limit=2, project_id=None, is_task=None, results=[], duration_ms=None,
+        suppressed=2,
+    )
+    assert p["result_count"] == 0
+    assert p["suppressed_count"] == 2, (
+        "a zero row that was really two repeats must be distinguishable from "
+        "a zero row where the ranker found nothing"
+    )
+
+
+def test_the_readout_reports_unmeasured_suppression_as_none():
+    """`_bucket` renders the aggregate. No row reporting it → null, never a
+    zeroed dict: a zeroed dict states a measurement nobody made."""
+    from scribe.services.retrieval_telemetry import _bucket
+
+    # calls, zero, p10, p50, p90, min, max, avg_n, dur,
+    # measured, supp_calls, supp_zero, miss_calls, miss_p50, miss_p90, miss_max
+    unmeasured = _bucket([326, 114, 0.6, 0.68, 0.77, 0.55, 0.85, 1.7, 130.9,
+                          0, 0, 0, 0, None, None, None])
+    assert unmeasured["suppression"] is None
+
+    measured = _bucket([35, 34, 0.75, 0.75, 0.75, 0.75, 0.75, 0.03, 51.9,
+                        35, 9, 9, 0, None, None, None])
+    assert measured["suppression"] == {
+        "measured_calls": 35,
+        "calls_with_suppression": 9,
+        "zero_because_already_shown": 9,
+    }
+    # The number the threshold is actually tuned from.
+    assert measured["zero_result_calls"] - 9 == 25
+
+
 def test_record_retrieval_without_event_loop_is_safe():
     """Called from a sync context (no running loop) it must swallow and return,
     never raise — telemetry can't be allowed to break a caller."""
@@ -162,7 +224,10 @@ async def test_retrieval_summary_reads_what_the_writer_wrote(_dispose_engine):
         ai = out["sources"]["auto_inject"]
         assert ai["calls"] == 4
         assert ai["zero_result_calls"] == 1
-        assert ai["cleared_threshold"] == 2      # 0.91 and 0.72, not 0.40
+        assert "cleared_threshold" not in ai, (
+            "the tautology is back: it was true exactly when result_count > 0, "
+            "so it reported nothing zero_result_calls did not (#3670)"
+        )
         # p50 over the three scored calls; the empty one contributes no score.
         assert ai["top_score"]["p50"] == pytest.approx(0.72, abs=1e-4)
         assert ai["top_score"]["min"] == pytest.approx(0.40, abs=1e-4)
@@ -195,6 +260,10 @@ async def test_retrieval_summary_is_empty_not_broken_for_a_fresh_install(_dispos
     assert out["sources"] == {}
     assert out["usage"]["pull_through"] is None   # no division by zero
     assert out["usage"]["surfaced"] == 0
+    # An empty dict, not a missing key and not a failure flag — the same
+    # "no rows" / "read broke" distinction the rest of this readout keeps.
+    assert out["usage"]["by_source"] == {}
+    assert "by_source_failed" not in out["usage"]
 
 
 @pytest.mark.integration
@@ -222,3 +291,752 @@ async def test_retrieval_summary_sees_only_its_own_users_telemetry(_dispose_engi
         async with async_session() as s:
             await s.execute(delete(RetrievalLog).where(RetrievalLog.user_id == 990004))
             await s.commit()
+
+
+# ─── per-source pull-through (#3311) ─────────────────────────────────────────
+# Integration for the same reason the block above is: this is a self-join with
+# two DISTINCT subqueries and a LIKE escape, which is a new SQL shape in a
+# module whose one production outage (#2663) was a new SQL shape the database
+# rejected inside a broad except. A mock would pass on a query Postgres refuses.
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_by_source_separates_a_surface_that_earns_its_noise_from_one_that_does_not(
+    _dispose_engine,
+):
+    """The whole point: the corpus average cannot say WHICH surface is working.
+
+    Two ranked surfaces, identical volume, opposite outcomes — and a top-level
+    ratio that describes neither of them.
+    """
+    from sqlalchemy import delete
+
+    from scribe.models import async_session
+    from scribe.models.note_usage import NoteUsageEvent
+    from scribe.services.retrieval_telemetry import retrieval_summary
+
+    UID = 990010
+    async with async_session() as s:
+        s.add_all([
+            # auto_inject chose note 1 three times and note 2 once. Three
+            # surfacings of one note is ONE note surfaced — the DISTINCT that
+            # keeps the join from multiplying rows is what this pins.
+            NoteUsageEvent(user_id=UID, note_id=1, event="surfaced", source="auto_inject"),
+            NoteUsageEvent(user_id=UID, note_id=1, event="surfaced", source="auto_inject"),
+            NoteUsageEvent(user_id=UID, note_id=1, event="surfaced", source="auto_inject"),
+            NoteUsageEvent(user_id=UID, note_id=2, event="surfaced", source="auto_inject"),
+            # write_path_semantic chose two notes and got nothing opened.
+            NoteUsageEvent(user_id=UID, note_id=3, event="surfaced", source="write_path_semantic"),
+            NoteUsageEvent(user_id=UID, note_id=4, event="surfaced", source="write_path_semantic"),
+            # One agent pull, of a note only auto_inject surfaced.
+            NoteUsageEvent(user_id=UID, note_id=1, event="pulled", source="mcp_get_note"),
+        ])
+        await s.commit()
+
+    try:
+        out = await retrieval_summary(UID, days=30)
+        assert out["read_failed"] is False
+        by_source = out["usage"]["by_source"]
+        assert "by_source_failed" not in out["usage"], "the join did not execute"
+
+        ai = by_source["auto_inject"]
+        assert ai["notes_surfaced"] == 2, "three surfacings of note 1 are one note"
+        assert ai["notes_pulled"] == 1
+        assert ai["pull_through"] == pytest.approx(0.5)
+
+        wp = by_source["write_path_semantic"]
+        assert wp["notes_surfaced"] == 2
+        assert wp["notes_pulled"] == 0
+        # 0.0, NOT None. "This surface produced nothing" is a finding; None is
+        # what a surface with no data reads as, and they must not look alike.
+        assert wp["pull_through"] == 0.0
+
+        # And the number that exists today, which is true of neither surface:
+        # one agent pull over six ranked surfacings.
+        assert out["usage"]["pull_through"] == pytest.approx(1 / 6, abs=1e-4)
+    finally:
+        async with async_session() as s:
+            await s.execute(delete(NoteUsageEvent).where(NoteUsageEvent.user_id == UID))
+            await s.commit()
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_an_ambient_surface_reports_its_counts_but_no_ratio(_dispose_engine):
+    """`enter_project` bulk-loads records; nothing CHOSE them. "Surfaced often,
+    opened never" is not a judgment about a record that was never picked, so the
+    counts stay visible and the ratio that would be misread is null."""
+    from sqlalchemy import delete
+
+    from scribe.models import async_session
+    from scribe.models.note_usage import NoteUsageEvent
+    from scribe.services.retrieval_telemetry import retrieval_summary
+
+    UID = 990011
+    async with async_session() as s:
+        s.add_all([
+            NoteUsageEvent(user_id=UID, note_id=1, event="surfaced", source="enter_project"),
+            NoteUsageEvent(user_id=UID, note_id=2, event="surfaced", source="enter_project"),
+        ])
+        await s.commit()
+
+    try:
+        row = (await retrieval_summary(UID, days=30))["usage"]["by_source"]["enter_project"]
+        assert row["ambient"] is True
+        assert row["notes_surfaced"] == 2
+        assert row["pull_through"] is None
+    finally:
+        async with async_session() as s:
+            await s.execute(delete(NoteUsageEvent).where(NoteUsageEvent.user_id == UID))
+            await s.commit()
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_the_agent_pull_filter_does_not_treat_its_underscore_as_a_wildcard(
+    _dispose_engine,
+):
+    """`_` is a LIKE wildcard, so an unescaped `LIKE 'mcp_%'` also matches
+    `mcpXsomething`. The Python half of this readout uses str.startswith and
+    cannot have the bug; the SQL half needs autoescape to match it, and nothing
+    else in the payload would reveal the difference."""
+    from sqlalchemy import delete
+
+    from scribe.models import async_session
+    from scribe.models.note_usage import NoteUsageEvent
+    from scribe.services.retrieval_telemetry import retrieval_summary
+
+    UID = 990012
+    async with async_session() as s:
+        s.add_all([
+            NoteUsageEvent(user_id=UID, note_id=1, event="surfaced", source="auto_inject"),
+            # Not an agent pull: the door is `mcpXget_note`, not `mcp_get_note`.
+            NoteUsageEvent(user_id=UID, note_id=1, event="pulled", source="mcpXget_note"),
+        ])
+        await s.commit()
+
+    try:
+        row = (await retrieval_summary(UID, days=30))["usage"]["by_source"]["auto_inject"]
+        assert row["notes_pulled"] == 0, "a wildcard match counted a non-agent pull"
+        assert row["pull_through"] == 0.0
+    finally:
+        async with async_session() as s:
+            await s.execute(delete(NoteUsageEvent).where(NoteUsageEvent.user_id == UID))
+            await s.commit()
+
+
+# ─── rule usage (milestone 333 step 3) ───────────────────────────────────────
+# Integration, for the same reason the block above is: these are real GROUP BYs
+# and count(distinct) against a table that did not exist a commit ago, in a
+# module whose one production outage (#2663) was a SQL shape the database
+# rejected inside a broad except. A mock would agree with whatever the code
+# does, including nothing.
+
+
+async def _rule_events(uid, rows):
+    """Write (event, source) pairs for one rule and hand back a cleanup."""
+    from sqlalchemy import delete
+
+    from scribe.models import async_session
+    from scribe.models.rule_usage import RuleUsageEvent
+
+    async with async_session() as s:
+        s.add_all([
+            RuleUsageEvent(user_id=uid, rule_id=rid, event=ev, source=src)
+            for rid, ev, src in rows
+        ])
+        await s.commit()
+
+    async def cleanup():
+        async with async_session() as s:
+            await s.execute(
+                delete(RuleUsageEvent).where(RuleUsageEvent.user_id == uid)
+            )
+            await s.commit()
+
+    return cleanup
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_rule_usage_is_a_coherent_zero_on_a_fresh_install(_dispose_engine):
+    """Every rule in an existing install predates this table, so "no events" is
+    the normal state for a while. It must read as zero, not as a missing key
+    and not as a failure — the same "no rows" / "read broke" distinction the
+    rest of this readout keeps (#2663).
+
+    `pull_through` is None rather than 0.0, matching the note block: a ratio of
+    zero asserts "rules were shown and none opened", which with an empty
+    numerator AND denominator is a claim the data does not support.
+    """
+    from scribe.services.retrieval_telemetry import retrieval_summary
+
+    out = await retrieval_summary(990010, days=30)
+    assert out["read_failed"] is False
+    assert "rule_usage_failed" not in out["rule_usage"]
+    assert out["rule_usage"]["surfaced"] == 0
+    assert out["rule_usage"]["pulled"] == 0
+    assert out["rule_usage"]["distinct_rules_surfaced"] == 0
+    assert out["rule_usage"]["pull_through"] is None
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_an_agent_reading_a_surfaced_rule_is_what_moves_the_ratio(_dispose_engine):
+    """The whole point of the milestone: the arm can now be told apart from a
+    bar it cannot fail to clear."""
+    from scribe.services.retrieval_telemetry import retrieval_summary
+
+    cleanup = await _rule_events(990011, [
+        (5001, "surfaced", "write_path_rule"),
+        (5002, "surfaced", "write_path_rule"),
+        (5001, "pulled", "mcp_get_rule"),
+    ])
+    try:
+        ru = (await retrieval_summary(990011, days=30))["rule_usage"]
+        assert ru["surfaced"] == 2
+        assert ru["pulled"] == 1
+        assert ru["pulled_by_agent"] == 1
+        assert ru["pulled_by_human"] == 0
+        assert ru["distinct_rules_surfaced"] == 2
+        assert ru["distinct_rules_pulled"] == 1
+        assert ru["pull_through"] == 0.5
+    finally:
+        await cleanup()
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_a_person_browsing_the_rule_list_does_not_move_the_ratio(_dispose_engine):
+    """The mcp_/rest_ split, and it carries more weight here than for notes.
+
+    The arm's claim is "this rule may apply to what you are writing". Only an
+    agent opening it says that claim landed; a person clicking through the rule
+    list in the web UI says nothing about the hint. Both are still counted in
+    `pulled`, so "is this rule dead weight?" stays answerable.
+    """
+    from scribe.services.retrieval_telemetry import retrieval_summary
+
+    cleanup = await _rule_events(990012, [
+        (5003, "surfaced", "write_path_rule"),
+        (5003, "pulled", "rest_rule"),
+    ])
+    try:
+        ru = (await retrieval_summary(990012, days=30))["rule_usage"]
+        assert ru["pulled"] == 1
+        assert ru["pulled_by_human"] == 1
+        assert ru["pulled_by_agent"] == 0
+        # Surfaced once, opened by nobody who matters to this question.
+        assert ru["pull_through"] == 0.0
+    finally:
+        await cleanup()
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_rule_events_stay_out_of_the_note_block(_dispose_engine):
+    """The separation, asserted rather than assumed.
+
+    `usage` is what existing callers already read and compare across windows.
+    If rule events leaked into it, that number would move for a reason nobody
+    was told about — and the rule arm would still be invisible, because a few
+    dozen rules against thousands of notes is noise on the note ratio.
+    """
+    from scribe.services.retrieval_telemetry import retrieval_summary
+
+    cleanup = await _rule_events(990013, [
+        (5004, "surfaced", "write_path_rule"),
+        (5004, "pulled", "mcp_get_rule"),
+    ])
+    try:
+        out = await retrieval_summary(990013, days=30)
+        assert out["rule_usage"]["surfaced"] == 1
+        # The note block saw none of it.
+        assert out["usage"]["surfaced"] == 0
+        assert out["usage"]["pulled"] == 0
+        assert out["usage"]["pull_through"] is None
+    finally:
+        await cleanup()
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_rule_usage_sees_only_its_own_users_events(_dispose_engine):
+    """Same access rule as the rest of the readout — the owner filter IS the
+    rule for telemetry, which is not a shared record kind."""
+    from scribe.services.retrieval_telemetry import retrieval_summary
+
+    cleanup = await _rule_events(990014, [
+        (5005, "surfaced", "write_path_rule"),
+        (5005, "pulled", "mcp_get_rule"),
+    ])
+    try:
+        assert (await retrieval_summary(990015, days=30))["rule_usage"]["surfaced"] == 0
+        assert (await retrieval_summary(990014, days=30))["rule_usage"]["surfaced"] == 1
+    finally:
+        await cleanup()
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_the_preload_lands_in_ambient_and_never_in_the_ratio(_dispose_engine):
+    """The split that makes the always-on set judgeable (#3473).
+
+    Pull-through asks "was that hint any use", and only a surface that CHOSE
+    what it showed can be judged by it. If the preload counted toward the
+    denominator, growing the always-on set would DEPRESS the arm's measured
+    precision and trimming it would flatter it — neither for any reason to do
+    with the arm. So the resident deliveries are counted, reported, and kept
+    out of the ratio.
+    """
+    from scribe.services.retrieval_telemetry import retrieval_summary
+
+    cleanup = await _rule_events(990012, [
+        # One rule the arm actually chose, and opened.
+        (5101, "surfaced", "write_path_rule"),
+        (5101, "pulled", "mcp_get_rule"),
+        # Four bulk deliveries across every shape of preload. Nobody chose any
+        # of them, and none may touch the denominator.
+        (5102, "surfaced", "session_start"),
+        (5103, "surfaced", "list_always_on_rules"),
+        (5104, "surfaced", "enter_project"),
+        (5105, "surfaced", "get_milestone"),
+    ])
+    try:
+        ru = (await retrieval_summary(990012, days=30))["rule_usage"]
+
+        assert ru["surfaced"] == 1, "only the arm chose a rule"
+        assert ru["ambient"] == 4, "the four bulk deliveries are reported, not dropped"
+
+        # 1 agent pull over 1 RANKED surfacing. Were the ambient four folded in
+        # the ratio would read 0.2 — the arm looking four times worse for
+        # having a large resident set beside it.
+        assert ru["pull_through"] == 1.0
+
+        # Dead-weight detection needs both classes: a rule delivered by the
+        # preload and never opened is the case that reading matters most for.
+        assert ru["distinct_rules_surfaced"] == 5
+        assert ru["distinct_rules_pulled"] == 1
+    finally:
+        await cleanup()
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_ambient_alone_reports_no_ratio(_dispose_engine):
+    """A brand-new install loads rules every session and may never trigger the
+    arm. That must read as "no ranked surfacings yet", not as a precision of
+    zero — the reading that would make a working install look broken."""
+    from scribe.services.retrieval_telemetry import retrieval_summary
+
+    cleanup = await _rule_events(990013, [
+        (5201, "surfaced", "session_start"),
+        (5202, "surfaced", "session_start"),
+    ])
+    try:
+        ru = (await retrieval_summary(990013, days=30))["rule_usage"]
+        assert ru["ambient"] == 2
+        assert ru["surfaced"] == 0
+        assert ru["pull_through"] is None
+    finally:
+        await cleanup()
+
+
+# ── Window coverage (#3712) ────────────────────────────────────────────
+#
+# A counter added last week, read over a 30-day window, reports a real count
+# against an imagined denominator. The result is a plausible FRACTION rather
+# than an obvious zero, which is what makes it dangerous — #379 spent five
+# planned steps on a defect that turned out to be a window opening before the
+# recording it was measuring existed.
+
+
+def test_coverage_says_nothing_rather_than_false_when_nothing_was_recorded():
+    """Null, never False. "No measurement" is not "partial measurement".
+
+    The same distinction `suppression`'s null carries (#3497): absent must not
+    read as a verdict. A False here would assert the window is under-covered,
+    which is a claim nobody is in a position to make.
+    """
+    from datetime import datetime, timezone
+
+    from scribe.services.retrieval_telemetry import _coverage
+
+    since = datetime(2026, 9, 1, tzinfo=timezone.utc)
+    assert _coverage(None, since) == {
+        "complete_from": None, "covers_window": None,
+    }
+
+
+def test_coverage_reads_a_start_before_the_window_as_covered():
+    from datetime import datetime, timezone
+
+    from scribe.services.retrieval_telemetry import _coverage
+
+    since = datetime(2026, 9, 1, tzinfo=timezone.utc)
+    older = datetime(2026, 8, 1, tzinfo=timezone.utc)
+    newer = datetime(2026, 9, 5, tzinfo=timezone.utc)
+
+    assert _coverage(older, since)["covers_window"] is True
+    assert _coverage(newer, since)["covers_window"] is False, (
+        "a counter that started inside the window covers only part of it"
+    )
+    assert _coverage(newer, since)["complete_from"] == newer.isoformat()
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_coverage_is_per_source_because_the_table_is_older_than_its_arms(
+    _dispose_engine,
+):
+    """THE grain question, and the reason a per-table answer is useless.
+
+    `retrieval_logs` accumulates for months. A table-level "earliest row"
+    therefore says months for every source it holds — including one added
+    days ago whose counter means something quite different. The old source
+    would vouch for the young one, which is exactly the reading this exists
+    to prevent.
+    """
+    from datetime import datetime, timedelta, timezone
+
+    from sqlalchemy import delete
+
+    from scribe.models import async_session
+    from scribe.models.retrieval_log import RetrievalLog
+    from scribe.services.retrieval_telemetry import retrieval_summary
+
+    UID = 990077
+    now = datetime.now(timezone.utc)
+    async with async_session() as s:
+        # An old surface, recording since well before any window we ask for,
+        # AND still recording inside it. Both rows are needed: `complete_from`
+        # comes from the all-time query, but a source only gets a bucket at all
+        # if it has rows in the window, so the 90-day row alone would leave
+        # nothing to assert on.
+        s.add(RetrievalLog(
+            user_id=UID, source="auto_inject", result_count=1,
+            created_at=now - timedelta(days=90),
+        ))
+        s.add(RetrievalLog(
+            user_id=UID, source="auto_inject", result_count=1,
+            created_at=now - timedelta(days=1),
+        ))
+        # A young arm, first written INSIDE the window below.
+        s.add(RetrievalLog(
+            user_id=UID, source="pre_tool_rule", result_count=1,
+            created_at=now - timedelta(days=2),
+        ))
+        await s.commit()
+
+    try:
+        out = await retrieval_summary(UID, days=30)
+
+        assert out["sources"]["auto_inject"]["covers_window"] is True
+        assert out["sources"]["pre_tool_rule"]["covers_window"] is False, (
+            "the young arm was reported as covering a 30-day window — the "
+            "table's age has been allowed to vouch for one of its sources"
+        )
+    finally:
+        async with async_session() as s:
+            await s.execute(delete(RetrievalLog).where(RetrievalLog.user_id == UID))
+            await s.commit()
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_a_surface_that_went_silent_is_not_the_same_as_one_that_never_ran(
+    _dispose_engine,
+):
+    """#3720 — absent is how "never existed" renders, so it cannot also be how
+    "stopped recording" renders.
+
+    A surface losing its recorder is one of the failures this milestone exists
+    to make visible, and dropping it from the readout is the most complete way
+    to hide it. Zero here is a real measurement: the table proves the source
+    was recording, and it made no calls across a window it fully covers.
+    """
+    from datetime import datetime, timedelta, timezone
+
+    from sqlalchemy import delete
+
+    from scribe.models import async_session
+    from scribe.models.retrieval_log import RetrievalLog
+    from scribe.services.retrieval_telemetry import retrieval_summary
+
+    UID = 990078
+    now = datetime.now(timezone.utc)
+    async with async_session() as s:
+        # Recorded once, well before the window, and never since.
+        s.add(RetrievalLog(
+            user_id=UID, source="auto_inject", result_count=3, top_score=0.81,
+            created_at=now - timedelta(days=60),
+        ))
+        await s.commit()
+
+    try:
+        out = await retrieval_summary(UID, days=7)
+
+        assert "auto_inject" in out["sources"], (
+            "a source with rows in the table but none in the window was "
+            "dropped from the readout — a surface that stopped recording now "
+            "reads exactly like one that never existed"
+        )
+        quiet = out["sources"]["auto_inject"]
+        assert quiet["calls"] == 0
+        # The window IS covered; what was observed across it is nothing.
+        assert quiet["covers_window"] is True
+        # ...but nothing was sampled, so no distribution may be claimed. A
+        # zeroed score would assert a measurement, which is #3311's mistake.
+        assert quiet["top_score"] == {
+            "p10": None, "p50": None, "p90": None, "min": None, "max": None,
+        }
+        assert quiet["suppression"] is None
+        assert quiet["avg_result_count"] is None
+    finally:
+        async with async_session() as s:
+            await s.execute(delete(RetrievalLog).where(RetrievalLog.user_id == UID))
+            await s.commit()
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_a_section_is_complete_only_from_its_latest_contributor(
+    _dispose_engine,
+):
+    """A sum is complete once EVERY contributor was being written — so the
+    section takes the LATEST first-row, not the earliest.
+
+    Taking the earliest would be worse than reporting nothing: it would pick
+    the oldest source in the table and use it to certify a total that a
+    newer source is still only partly contributing to. That is the original
+    error in miniature.
+    """
+    from datetime import datetime, timedelta, timezone
+
+    from sqlalchemy import delete
+
+    from scribe.models import async_session
+    from scribe.models.rule_usage import RuleUsageEvent
+    from scribe.services.retrieval_telemetry import retrieval_summary
+
+    UID = 990078
+    now = datetime.now(timezone.utc)
+    old = now - timedelta(days=90)
+    young = now - timedelta(days=2)
+    async with async_session() as s:
+        s.add_all([
+            RuleUsageEvent(
+                user_id=UID, rule_id=1, event="surfaced",
+                source="list_always_on_rules", created_at=old,
+            ),
+            RuleUsageEvent(
+                user_id=UID, rule_id=2, event="surfaced",
+                source="pre_tool_rule", created_at=young,
+            ),
+        ])
+        await s.commit()
+
+    try:
+        out = await retrieval_summary(UID, days=30)
+        ru = out["rule_usage"]
+
+        assert ru["complete_from"] == young.isoformat(), (
+            "the section reported completeness from its OLDEST source; a "
+            "total is only as complete as its newest contributor"
+        )
+        assert ru["covers_window"] is False
+    finally:
+        async with async_session() as s:
+            await s.execute(delete(RuleUsageEvent).where(RuleUsageEvent.user_id == UID))
+            await s.commit()
+
+
+# ─── the bar can only be judged from what it rejected (#3670) ────────────────
+#
+# `cleared_threshold` was the number the docstring told a reader to look at
+# first. It was `calls - zero_result_calls` under another name: the search
+# applies the bar before returning, so every returned result cleared it by
+# construction and a call with nothing has no score to compare.
+# `zero_result_calls + cleared_threshold == calls` held on all nineteen
+# source/window readings ever taken — no near-misses, no exceptions.
+#
+# What replaced it cannot go the same way, and the reason is structural rather
+# than careful naming: `near_misses` is measured on the calls the bar TURNED
+# AWAY, using a score the bar never saw. No arrangement of `calls`,
+# `zero_result_calls` and `result_count` derives it.
+
+
+def test_a_call_that_returned_nothing_still_records_what_it_nearly_showed():
+    """The whole point, at the payload grain.
+
+    This is the row a threshold is tuned from and the one that used to carry no
+    score at all: `top_score` and `min_score` are both null here, correctly, and
+    a reader was left unable to tell a bar rejecting 0.71s from one rejecting
+    0.30s. Both render as a zero-result call.
+    """
+    p = _build_payload(
+        user_id=1, source="pre_tool_rule", query="git push --force",
+        threshold=0.72, limit=1, project_id=None, is_task=None,
+        results=[], duration_ms=None, best_available=0.7104,
+    )
+    assert p["result_count"] == 0
+    assert p["top_score"] is None, "nothing was shown, so nothing has a top score"
+    assert p["best_available_score"] == 0.7104, (
+        "the losing score was discarded — the only figure that survives a call "
+        "returning nothing, and the only one a bar can be judged from"
+    )
+
+
+def test_a_caller_that_did_not_measure_the_near_miss_stores_null():
+    """Null, never 0.0. A zero here reads as "the corpus held nothing remotely
+    relevant" — a claim about the corpus invented out of a caller's silence,
+    which is #3311's substitution in a new field."""
+    p = _build_payload(
+        user_id=1, source="auto_inject", query="q", threshold=0.6,
+        limit=3, project_id=None, is_task=None, results=[], duration_ms=None,
+    )
+    assert p["best_available_score"] is None
+
+
+def test_the_readout_reports_unmeasured_near_misses_as_none():
+    """`_bucket`'s half of the same discipline, and the reason it is a block
+    rather than three loose keys: old rows predate the column, so a window can
+    legitimately contain declines nobody measured."""
+    from scribe.services.retrieval_telemetry import _bucket
+
+    # calls, zero, p10, p50, p90, min, max, avg_n, dur,
+    # measured, supp_calls, supp_zero, miss_calls, miss_p50, miss_p90, miss_max
+    none_measured = _bucket([326, 114, 0.6, 0.68, 0.77, 0.55, 0.85, 1.7, 130.9,
+                             0, 0, 0, 0, None, None, None])
+    assert none_measured["near_misses"] is None
+
+    measured = _bucket([326, 114, 0.6, 0.68, 0.77, 0.55, 0.85, 1.7, 130.9,
+                        0, 0, 0, 114, 0.61, 0.7104, 0.7189])
+    assert measured["near_misses"] == {
+        "measured_calls": 114,
+        "p50": 0.61,
+        "p90": 0.7104,
+        "max": 0.7189,
+    }
+
+
+def test_the_readout_carries_no_field_derivable_from_its_neighbours():
+    """The guard that would have caught #3670 on the day it shipped.
+
+    `cleared_threshold` survived because it had its own name and its own
+    docstring paragraph, and nobody added the two numbers beside it. This
+    asserts the identity that held on every reading ever taken — and if a
+    future field reintroduces it under a new name, the sum below is where it
+    shows up.
+    """
+    from scribe.services.retrieval_telemetry import _bucket
+
+    b = _bucket([326, 114, 0.6, 0.68, 0.77, 0.55, 0.85, 1.7, 130.9,
+                 0, 0, 0, 114, 0.61, 0.71, 0.72])
+    derivable = {
+        k for k, v in b.items()
+        if isinstance(v, int) and not isinstance(v, bool)
+        and k not in ("calls", "zero_result_calls")
+        and v == b["calls"] - b["zero_result_calls"]
+    }
+    assert not derivable, (
+        f"{sorted(derivable)} equals calls - zero_result_calls on this row. "
+        f"That is how `cleared_threshold` read for its whole life (#3670): a "
+        f"figure presented as an independent measurement that a reader can "
+        f"compute from the two numbers next to it. Either it is a tautology, "
+        f"or this fixture happens to make it look like one — check which "
+        f"before adding an exemption."
+    )
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_the_near_miss_distribution_is_a_query_postgres_accepts(_dispose_engine):
+    """Integration, and NOT belt-and-braces on the unit tests above.
+
+    `near_misses` is a `percentile_cont(...) WITHIN GROUP` over a CASE
+    expression, inside the same grouped aggregate that already carries four
+    other CASEs. That is within one step of the shape that produced #2663 — a
+    query the database rejected, swallowed by this module's broad `except`, so
+    every counter read zero in production while the writes landed fine and the
+    mocked tests passed. Only a real Postgres can say this parses, and if it
+    does not, the symptom is silence rather than an error.
+
+    The numbers are chosen so a bar at 0.72 is visibly the wrong bar: three
+    declines at 0.70, 0.71 and 0.7189, none of which a reader could see before.
+    """
+    from sqlalchemy import delete
+
+    from scribe.models import async_session
+    from scribe.models.retrieval_log import RetrievalLog
+    from scribe.services.retrieval_telemetry import (
+        _insert_retrieval_log, retrieval_summary,
+    )
+
+    UID = 990079
+    for best in (0.70, 0.71, 0.7189):
+        await _insert_retrieval_log(_build_payload(
+            user_id=UID, source="pre_tool_rule", query="git push", threshold=0.72,
+            limit=1, project_id=None, is_task=None, results=[],
+            duration_ms=4.0, best_available=best,
+        ))
+    # A call that DID show something. Its best-available equals its top score,
+    # so including it would drag the distribution toward the scores the bar
+    # already accepts — the population has to be the declines alone.
+    await _insert_retrieval_log(_build_payload(
+        user_id=UID, source="pre_tool_rule", query="curl", threshold=0.72,
+        limit=1, project_id=None, is_task=None,
+        results=[(0.88, _note(7))], duration_ms=4.0, best_available=0.88,
+    ))
+    # An unmeasured decline, standing in for every row written before #3670.
+    await _insert_retrieval_log(_build_payload(
+        user_id=UID, source="pre_tool_rule", query="ls", threshold=0.72,
+        limit=1, project_id=None, is_task=None, results=[], duration_ms=4.0,
+    ))
+    # THE CASE WHOSE ABSENCE LET THIS GUARD PASS OVER BROKEN CODE (#3739).
+    # A zero-result call whose zero was a REPEAT, not a rejection: the ranker
+    # cleared the bar at 0.9 and the session had already been shown that rule,
+    # so the arm dropped it in Python after the search. Without the suppression
+    # arm of the predicate this row lands in the near-miss population and drags
+    # `max` to 0.9 — above the very threshold the field is read against.
+    await _insert_retrieval_log(_build_payload(
+        user_id=UID, source="pre_tool_rule", query="git commit", threshold=0.72,
+        limit=1, project_id=None, is_task=None, results=[], duration_ms=4.0,
+        best_available=0.9, suppressed=1,
+    ))
+
+    try:
+        out = await retrieval_summary(UID, days=30)
+        assert out["read_failed"] is False, (
+            "the aggregate did not execute — a rejected query here reads as "
+            "zeros everywhere, which is #2663 exactly"
+        )
+        src = out["sources"]["pre_tool_rule"]
+        assert src["calls"] == 6
+        assert src["zero_result_calls"] == 5
+
+        nm = src["near_misses"]
+        assert nm is not None, "the near-miss block did not survive the query"
+        assert nm["measured_calls"] == 3, (
+            "the population is declines the BAR caused, that recorded a score. "
+            "Three qualify. Excluded: the unmeasured row (predates the column, "
+            "not a scoreless decline), the call that showed something (its "
+            "best-available is just its top score), and the REPEAT — a zero "
+            "the reader caused, not the bar (#3739)"
+        )
+        assert nm["max"] == pytest.approx(0.7189, abs=1e-4), (
+            "the closest thing the bar turned away — 0.7189 against a 0.72 "
+            "threshold, which is the reading the whole field exists to give"
+        )
+        assert nm["max"] < 0.72, (
+            "a rejection that outscores the bar is not a rejection. This is "
+            "structural once the suppression arm is in the predicate: an "
+            "above-bar candidate that was not excluded would have been "
+            "RETURNED, so its call cannot be in this population (#3739)"
+        )
+        assert 0.70 <= nm["p50"] <= 0.7189
+    finally:
+        async with async_session() as s:
+            await s.execute(delete(RetrievalLog).where(RetrievalLog.user_id == UID))
+            await s.commit()

tests/test_services_rule_usage.py

@@ -0,0 +1,257 @@
+"""Rule usage telemetry — the parts that need no database (milestone 333 step 1).
+
+The round trip lives in `test_integration_backup_rule_usage_roundtrip.py`.
+What is here is the payload building and the zero shape: cheap, and the half
+where a mistake is silent rather than loud.
+"""
+import pytest
+
+from scribe.models.rule_usage import PULLED, SURFACED, RuleUsageEvent
+from scribe.services import rule_usage
+
+
+@pytest.fixture
+def captured(monkeypatch):
+    """Intercept the scheduler so the payload can be read without a loop.
+
+    Patching `_schedule` rather than `background.spawn` keeps the test on this
+    module's own seam: what is under test is which rows get built, not whether
+    the shared fire-and-forget machinery works — that has its own home.
+    """
+    rows: list[list[dict]] = []
+    monkeypatch.setattr(rule_usage, "_schedule", rows.append)
+    return rows
+
+
+def test_a_surfacing_records_one_row_per_rule(captured):
+    """The arm shows a hint containing several rules at once; each needs its
+    own row, because the readout is per rule."""
+    rule_usage.record_rule_surfaced(
+        user_id=7, rule_ids=[156, 157], source="write_path_rule"
+    )
+    [batch] = captured
+    assert batch == [
+        {"user_id": 7, "rule_id": 156, "event": SURFACED, "source": "write_path_rule"},
+        {"user_id": 7, "rule_id": 157, "event": SURFACED, "source": "write_path_rule"},
+    ]
+
+
+def test_the_whole_hint_lands_as_one_batch(captured):
+    """One scheduled insert for the hint, not one per rule. A hint is a single
+    decision and its rows should land together — a partial batch would read as
+    a hint that surfaced fewer rules than it did."""
+    rule_usage.record_rule_surfaced(
+        user_id=7, rule_ids=[1, 2, 3], source="write_path_rule"
+    )
+    assert len(captured) == 1
+    assert len(captured[0]) == 3
+
+
+def test_a_pull_records_one_row(captured):
+    rule_usage.record_rule_pulled(user_id=7, rule_id=156, source="mcp_get_rule")
+    assert captured == [
+        [{"user_id": 7, "rule_id": 156, "event": PULLED, "source": "mcp_get_rule"}]
+    ]
+
+
+def test_an_actorless_event_is_still_recorded(captured):
+    """The arm fires from a hook that may carry no authenticated user. Dropping
+    those would silently shrink the denominator the ratio divides by — the
+    surfacings would vanish while any later pull still counted."""
+    rule_usage.record_rule_surfaced(
+        user_id=None, rule_ids=[156], source="write_path_rule"
+    )
+    assert captured[0][0]["user_id"] is None
+
+
+def test_an_empty_surfacing_builds_no_rows(captured):
+    """The arm can rank everything out — `exclude_rule_ids` drops what the
+    session already holds. That is not a surfacing, and the empty batch is
+    where `_schedule` returns early rather than opening a session to insert
+    nothing."""
+    rule_usage.record_rule_surfaced(user_id=7, rule_ids=[], source="write_path_rule")
+    assert captured == [[]]
+
+
+def test_the_real_scheduler_returns_early_on_an_empty_batch():
+    """The guard itself, against the REAL `_schedule` the stub above replaces.
+
+    There is no running loop in a unit test, so `spawn` would be harmless
+    anyway — but it would build a coroutine only to close it, and the point is
+    that an empty batch never gets that far.
+    """
+    rule_usage._schedule([])  # must not raise
+
+
+def test_a_bad_rule_id_is_dropped_not_raised(captured):
+    """Telemetry must never break the surface it observes. An unconvertible id
+    is a bug somewhere upstream, and the right response is to lose the row and
+    log it — not to take down the write-path hint."""
+    rule_usage.record_rule_pulled(
+        user_id=7, rule_id="not-an-int", source="mcp_get_rule"  # type: ignore[arg-type]
+    )
+    assert captured == []
+
+
+def test_the_zero_readout_names_every_key():
+    """Callers render this shape unconditionally. Every rule in an existing
+    install predates the table, so for a while "no events" is the NORMAL state
+    — a missing key here would read as a broken readout on almost every row."""
+    assert rule_usage.empty_rule_usage() == {
+        "surfaced_count": 0,
+        "ambient_count": 0,
+        "pull_count": 0,
+        "last_surfaced_at": None,
+        "last_pulled_at": None,
+    }
+
+
+def test_only_a_ranker_counts_as_ranked():
+    """The bulk surfaces are ambient; the write-path arm is the only chooser.
+
+    Inverted against the note twin on purpose (see the module docstring): the
+    RARE half is the one that gets named, so a bulk surface added later and
+    forgotten defaults to ambient — under-counting it — instead of defaulting
+    to ranked and padding the pull-through denominator with surfacings nobody
+    chose.
+    """
+    assert not rule_usage.is_ambient("write_path_rule")
+    for bulk in (
+        "session_start", "list_always_on_rules", "enter_project",
+        "get_project", "get_milestone", "start_planning", "get_task",
+    ):
+        assert rule_usage.is_ambient(bulk), bulk
+    # The safe default is the whole point of the inversion.
+    assert rule_usage.is_ambient("some_surface_invented_next_year")
+
+
+def test_the_model_serialises_the_fields_the_ratio_needs():
+    ev = RuleUsageEvent(
+        user_id=7, rule_id=156, event=SURFACED, source="write_path_rule"
+    )
+    row = ev.to_dict()
+    assert row["rule_id"] == 156
+    assert row["event"] == SURFACED
+    assert row["source"] == "write_path_rule"
+    # created_at is server-defaulted, so it is None until the row is flushed —
+    # `iso()` must tolerate that rather than raising on a fresh instance.
+    assert row["created_at"] is None
+
+
+# ─── the readout (milestone 333 step 5) ──────────────────────────────────────
+# Integration: a real GROUP BY over a real table. Step 1 unit-tested the WRITE
+# path and the zero shape and left the aggregate uncovered, which only became
+# load-bearing when the rule list started rendering it.
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_usage_for_rules_aggregates_per_rule(_dispose_engine):
+    from sqlalchemy import delete
+
+    from scribe.models import async_session
+    from scribe.models.rule_usage import RuleUsageEvent
+
+    async with async_session() as s:
+        s.add_all([
+            RuleUsageEvent(user_id=990020, rule_id=6001,
+                           event=SURFACED, source="write_path_rule"),
+            RuleUsageEvent(user_id=990020, rule_id=6001,
+                           event=SURFACED, source="write_path_rule"),
+            RuleUsageEvent(user_id=990020, rule_id=6001,
+                           event=PULLED, source="mcp_get_rule"),
+            RuleUsageEvent(user_id=990020, rule_id=6002,
+                           event=SURFACED, source="write_path_rule"),
+        ])
+        await s.commit()
+    try:
+        out = await rule_usage.usage_for_rules([6001, 6002, 6003])
+
+        assert out[6001]["surfaced_count"] == 2
+        assert out[6001]["pull_count"] == 1
+        assert out[6001]["last_surfaced_at"] is not None
+        assert out[6001]["last_pulled_at"] is not None
+
+        # Surfaced twice as often as it was opened — never, in this case.
+        assert out[6002]["surfaced_count"] == 1
+        assert out[6002]["pull_count"] == 0
+        assert out[6002]["last_pulled_at"] is None
+
+        # A rule with NO events still comes back, zero-filled. The caller must
+        # never have to tell "no events" from "not in the result" — and on any
+        # existing install that is nearly every rule.
+        assert out[6003] == rule_usage.empty_rule_usage()
+
+        # Nothing ambient in this fixture, so the ambient bucket stays empty
+        # rather than absorbing the ranked hits.
+        assert out[6001]["ambient_count"] == 0
+    finally:
+        async with async_session() as s:
+            await s.execute(
+                delete(RuleUsageEvent).where(RuleUsageEvent.user_id == 990020)
+            )
+            await s.commit()
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_usage_for_rules_on_an_empty_id_list_asks_the_database_nothing(
+    _dispose_engine,
+):
+    """The list route calls this with whatever the page holds, which on an
+    empty topic is nothing. An unguarded `IN ()` is both a pointless round trip
+    and, on some drivers, a syntax error."""
+    assert await rule_usage.usage_for_rules([]) == {}
+
+
+@pytest.mark.integration
+@pytest.mark.asyncio
+async def test_a_preloaded_rule_does_not_read_as_a_ranked_surfacing(_dispose_engine):
+    """The split that makes the always-on set judgeable (#3473).
+
+    A resident rule is delivered every session by a surface that chose
+    nothing. Counting those as `surfaced_count` would rank the always-on set
+    as the most-surfaced rules in the install purely for being resident — and
+    the badge's "shown often, opened never → dead weight" reading, which is
+    the whole reason the counter exists, would then be exactly backwards.
+    """
+    from sqlalchemy import delete
+
+    from scribe.models import async_session
+    from scribe.models.rule_usage import RuleUsageEvent
+
+    async with async_session() as s:
+        s.add_all([
+            # Delivered by the preload three times over: ambient, all of it.
+            RuleUsageEvent(user_id=990021, rule_id=6101,
+                           event=SURFACED, source="session_start"),
+            RuleUsageEvent(user_id=990021, rule_id=6101,
+                           event=SURFACED, source="list_always_on_rules"),
+            RuleUsageEvent(user_id=990021, rule_id=6101,
+                           event=SURFACED, source="enter_project"),
+            # ...and once by the arm, which DID choose it.
+            RuleUsageEvent(user_id=990021, rule_id=6101,
+                           event=SURFACED, source="write_path_rule"),
+            # Opened once after a hint and once from the list: pulls are pulls
+            # however the rule was found, so both land in the one counter.
+            RuleUsageEvent(user_id=990021, rule_id=6101,
+                           event=PULLED, source="mcp_get_rule"),
+            RuleUsageEvent(user_id=990021, rule_id=6101,
+                           event=PULLED, source="rest_rule"),
+        ])
+        await s.commit()
+    try:
+        out = await rule_usage.usage_for_rules([6101])
+
+        assert out[6101]["surfaced_count"] == 1, "only the arm chose this rule"
+        assert out[6101]["ambient_count"] == 3, "three bulk deliveries"
+        # Both PULLED rows accumulate — the loop ADDS rather than assigns, so a
+        # rule opened after a hint and again from the list reports two, not one.
+        assert out[6101]["pull_count"] == 2
+        assert out[6101]["last_pulled_at"] is not None
+    finally:
+        async with async_session() as s:
+            await s.execute(
+                delete(RuleUsageEvent).where(RuleUsageEvent.user_id == 990021)
+            )
+            await s.commit()

tests/test_session_context_ledger.py

@@ -0,0 +1,158 @@
+"""The SessionStart hook clears the rule ledger exactly when context dies (#3749).
+
+WHY THIS EXISTS
+
+The prior-art and tool-rule hooks record every rule id they have named in
+`<state>/<sid>.rules.ids` and hand it back as `exclude_rule_ids`, so a rule is
+surfaced once per session and then goes quiet. That is correct while the
+session still holds what it was told.
+
+A compaction breaks that assumption in the worst available way: it summarizes
+the earlier injections out of context and does not touch the filesystem. The
+rule ends up absent from context AND still excluded — unreachable for the rest
+of the session. The compaction banner tells the model to re-pull its
+*always-on* rules, but a rule an arm surfaced is conditional and is not in that
+set, so it has no other way back. The rules most likely to be in that state are
+the ones that fire most often.
+
+WHAT THIS PINS
+
+Not "the ledger is cleared" — that would pass against a hook which deletes it
+on every source, and deleting on `resume` is its own defect: the context was
+genuinely restored there, so re-surfacing every rule is the mirror error.
+
+What is pinned is the DISCRIMINATION. The whole source table is asserted in one
+statement, so a blanket delete (all False) and a no-op (all True) both fail,
+and neither can be made to pass by editing one case.
+
+Runs the real shell against a temp TMPDIR, like the after-write hook's tests.
+Deliberately with no SCRIBE_URL/SCRIBE_TOKEN in the environment: clearing the
+ledger is local, keyless and networkless, and must still happen on an instance
+that is unreachable or unconfigured.
+"""
+from __future__ import annotations
+
+import json
+import os
+import shutil
+import subprocess
+from pathlib import Path
+
+import pytest
+
+PLUGIN = Path(__file__).resolve().parents[1] / "plugin"
+HOOK = PLUGIN / "hooks" / "scribe_session_context.sh"
+
+
+def _env(tmp_path):
+    """Near-namesake of test_after_write_hook's `_env`, and deliberately not it:
+    that one needs git and curl and SUPPLIES credentials, because the behaviour
+    it tests is a network round-trip. This one must prove the opposite — that
+    the clear happens with no credentials and no network at all — so sharing a
+    helper would mean testing this case in an environment that cannot show it.
+    """
+    for tool in ("jq", "bash"):
+        if shutil.which(tool) is None:
+            pytest.skip(f"hook runtime tool {tool!r} not installed")
+    # No SCRIBE_URL / SCRIBE_TOKEN on purpose — see the module docstring.
+    return {"PATH": os.environ["PATH"], "TMPDIR": str(tmp_path),
+            "HOME": str(tmp_path)}
+
+
+def _ledger(tmp_path, sid: str, name: str = "rules.ids") -> Path:
+    d = tmp_path / "scribe-priorart"
+    d.mkdir(exist_ok=True)
+    f = d / f"{sid}.{name}"
+    f.write_text("156\n168\n")
+    return f
+
+
+def _fire(source: str, sid: str, env) -> None:
+    subprocess.run(
+        ["bash", str(HOOK)],
+        input=json.dumps({"source": source, "session_id": sid}),
+        capture_output=True, text=True, env=env, timeout=30,
+    )
+
+
+def test_the_rules_ledger_survives_exactly_when_the_context_does(tmp_path):
+    """The whole source table, in one assertion, so it cannot be half-satisfied.
+
+    `startup` is listed even though it is a no-op against a session id that has
+    never been seen: it is asserted here so that a future change which starts
+    clearing indiscriminately fails on a case somebody would otherwise call
+    harmless.
+    """
+    env = _env(tmp_path)
+    survived = {}
+    for source in ("compact", "clear", "resume", "startup"):
+        sid = f"sess-{source}"
+        ledger = _ledger(tmp_path, sid)
+        _fire(source, sid, env)
+        survived[source] = ledger.exists()
+
+    assert survived == {
+        "compact": False,
+        "clear": False,
+        "resume": True,
+        "startup": True,
+    }, (
+        f"got {survived}. A rule surfaced before a compaction is summarized "
+        f"out of context while its id stays on the exclusion ledger, so it "
+        f"becomes unreachable for the rest of the session — that is what the "
+        f"compact/clear cases prevent. The resume case is the other half: the "
+        f"context came back intact there, and re-surfacing every rule after a "
+        f"restore that lost nothing is the same defect from the other side. "
+        f"All-False means something is deleting unconditionally; all-True "
+        f"means the clear never runs."
+    )
+
+
+def test_only_the_rule_ledger_is_cleared_and_the_note_ledgers_are_left(tmp_path):
+    """Scope, asserted rather than described.
+
+    The same directory holds `.ids`, `.sync.ids` and `.derive.ids` for the note
+    arms. Whether a surfaced NOTE should come back after a compaction is a
+    different question with a different answer, and it is not being answered.
+    A `rm` glob over `<sid>.*` would pass every assertion in the test above
+    while silently deciding it.
+    """
+    env = _env(tmp_path)
+    sid = "sess-scope"
+    rules = _ledger(tmp_path, sid, "rules.ids")
+    notes = _ledger(tmp_path, sid, "ids")
+    sync = _ledger(tmp_path, sid, "sync.ids")
+    derive = _ledger(tmp_path, sid, "derive.ids")
+
+    _fire("compact", sid, env)
+
+    assert not rules.exists(), "the rule ledger should have been cleared"
+    assert notes.exists() and sync.exists() and derive.exists(), (
+        "a note ledger was cleared too. The note arms were deliberately left "
+        "out of #3749 — clearing them is a decision about a different surface, "
+        "and a glob that takes them along makes it by accident."
+    )
+
+
+def test_a_compact_without_a_session_id_is_survivable(tmp_path):
+    """Defensive, because this hook's contract is fail-open.
+
+    An event with no `session_id` names no ledger. The hook must not error, and
+    must not fall back to a wildcard — clearing every session's ledger on the
+    machine because this one event was malformed is the worst available
+    reading of "best effort".
+    """
+    env = _env(tmp_path)
+    other = _ledger(tmp_path, "someone-elses-session")
+
+    proc = subprocess.run(
+        ["bash", str(HOOK)],
+        input=json.dumps({"source": "compact"}),
+        capture_output=True, text=True, env=env, timeout=30,
+    )
+
+    assert proc.returncode == 0, proc.stderr
+    assert other.exists(), (
+        "an event with no session id cleared a ledger belonging to a different "
+        "session"
+    )

tests/test_version_endpoint.py

@@ -0,0 +1,182 @@
+"""`/api/version` reports three values, and never folds them together.
+
+WHAT THIS IS ABOUT (rule 149). Until 2026-08-31 the endpoint returned
+`{"version": "main"}` — CI set `BUILD_VERSION` to the CHANNEL, so a running
+instance answered the question "which build are you?" with the name of a
+branch. The cost was concrete rather than theoretical: during #3244's live
+acceptance a deploy was behaving as though it held older code, and the one
+endpoint whose job is to settle that could not.
+
+The three values answer different questions and so cannot be one value:
+
+  version  the NAME, from COMMIT time   — "is this the same code?"
+  build    the ORDERING KEY, BUILD time — "may this be installed over that?"
+  channel  its own field                — "which line is this?"
+
+These pin the SHAPE the lanes emit, not the values — a test asserting today's
+timestamp would fail tomorrow, and one asserting the format catches the thing
+that actually breaks: a channel creeping back into the name, or an ordering
+key that is not orderable.
+"""
+import os
+import pathlib
+import re
+from datetime import datetime, timezone
+from unittest.mock import patch
+
+import pytest
+
+CI = pathlib.Path(__file__).resolve().parents[1] / ".forgejo/workflows/ci.yml"
+
+# The NAME's shape: four dot-separated numeric fields, zero-padded, and
+# nothing else. A channel token anywhere in here is the bug this file exists
+# to prevent.
+NAME_RE = re.compile(r"^\d{4}\.\d{2}\.\d{2}\.\d{4}$")
+
+
+_ENV_KEYS = ("APP_VERSION", "APP_BUILD_KEY", "APP_CHANNEL", "APP_COMMIT")
+
+
+def _version_payload(env: dict) -> dict:
+    """The real payload builder, under a controlled environment.
+
+    Calls `build_version_payload` rather than the route: the payload is the
+    behaviour, and reaching it through an app and a request context would
+    make these tests depend on app startup to assert a dict. The route is a
+    one-line `jsonify` wrapper over this.
+    """
+    from scribe.routes.api import build_version_payload
+
+    with patch.dict(os.environ, env, clear=False):
+        # patch.dict cannot REMOVE, and "absent" is exactly what several of
+        # these assert — so anything the caller left out is cleared.
+        for key in _ENV_KEYS:
+            if key not in env:
+                os.environ.pop(key, None)
+        return build_version_payload()
+
+
+def test_the_three_values_are_three_fields():
+    """The headline. One field cannot answer three questions, and the failure
+    mode of trying is silent: the string looks plausible and orders wrong."""
+    out = _version_payload({
+        "APP_VERSION": "2026.08.31.0403",
+        "APP_BUILD_KEY": "3505443",
+        "APP_CHANNEL": "stable",
+        "APP_COMMIT": "b267037",
+    })
+    assert out["version"] == "2026.08.31.0403"
+    assert out["build"] == 3505443
+    assert out["channel"] == "stable"
+    assert out["commit"] == "b267037"
+
+
+def test_the_channel_is_never_inside_the_name():
+    """The regression itself. `{"version": "main"}` is what this catches."""
+    out = _version_payload({
+        "APP_VERSION": "2026.08.31.0403", "APP_CHANNEL": "stable",
+    })
+    assert NAME_RE.match(out["version"]), (
+        f"the version name is {out['version']!r} — not YYYY.MM.DD.HHMM. A "
+        f"channel or branch name here is the 2026-08-31 bug returning."
+    )
+    assert "stable" not in out["version"]
+
+
+def test_the_ordering_key_is_an_INTEGER():
+    """A string ordering key is how a comparison silently becomes
+    lexicographic — "9" > "10" — which reads fine and orders wrong."""
+    out = _version_payload({"APP_VERSION": "x", "APP_BUILD_KEY": "3505443"})
+    assert isinstance(out["build"], int)
+    assert not isinstance(out["build"], bool)
+
+
+def test_unknown_values_are_ABSENT_not_empty():
+    """A local build genuinely has no ordering key and no channel. Emitting
+    `""` or a placeholder would let it claim a position in an update order it
+    is not part of; a reader must see "cannot be ordered", not zero."""
+    out = _version_payload({"APP_VERSION": "dev"})
+    assert out == {"version": "dev"}
+    assert "build" not in out and "channel" not in out and "commit" not in out
+
+
+def test_an_empty_env_var_counts_as_absent():
+    """Docker sets an ARG with no default to the empty string, so "unset" and
+    "set to nothing" both reach the handler as ''."""
+    out = _version_payload({
+        "APP_VERSION": "dev", "APP_CHANNEL": "", "APP_BUILD_KEY": "",
+        "APP_COMMIT": "   ",
+    })
+    assert out == {"version": "dev"}
+
+
+def test_a_malformed_ordering_key_is_dropped_not_passed_through():
+    """A reader that cannot order is correct; one that orders on garbage is
+    not. Dropping it degrades to "unorderable", which is a state the caller
+    already has to handle."""
+    out = _version_payload({"APP_VERSION": "dev", "APP_BUILD_KEY": "main"})
+    assert "build" not in out
+
+
+def test_the_channel_is_reported_verbatim():
+    """Never validated against an enum — a build claiming something
+    unexpected is better shown than dropped (rule 149)."""
+    out = _version_payload({"APP_VERSION": "dev", "APP_CHANNEL": "canary"})
+    assert out["channel"] == "canary"
+
+
+# ── The lane, as CI actually writes it ─────────────────────────────────
+
+def test_ci_does_not_stamp_the_channel_as_the_version():
+    """The bug lived in the workflow, not the handler. A correct handler fed
+    `BUILD_VERSION=main` still reports a branch name."""
+    text = CI.read_text()
+    assert "BUILD_VERSION=${{ steps.tags.outputs.build_name }}" in text, (
+        "CI no longer passes the derived NAME as BUILD_VERSION. If it is "
+        "passing a branch or channel again, /api/version is lying."
+    )
+    for wrong in ('BUILD_VERSION="main"', 'BUILD_VERSION="dev"'):
+        assert wrong not in text, (
+            f"CI sets {wrong} — that is the channel in the version field, "
+            f"which is the 2026-08-31 regression."
+        )
+
+
+def test_ci_derives_the_name_from_COMMIT_time_and_the_key_from_BUILD_time():
+    """The two clocks are deliberate and easy to "tidy" into one.
+
+    The name must come from the commit so two lanes building one source agree;
+    the key must come from the build so it cannot go backwards when an older
+    commit is rebuilt. Collapsing them breaks whichever question loses.
+    """
+    text = CI.read_text()
+    assert "git log --format=%ct -1 HEAD" in text, (
+        "the version NAME is no longer derived from commit time — two lanes "
+        "building the same commit will now report different strings"
+    )
+    assert "$(date -u +%s) - 1577836800" in text, (
+        "the ORDERING KEY is no longer minutes-since-2020 from build time; "
+        "if it now comes from the commit it can go backwards on a rebuild"
+    )
+
+
+def test_ci_passes_all_three_plus_the_commit():
+    text = CI.read_text()
+    for arg in ("BUILD_KEY=", "BUILD_CHANNEL=", "BUILD_COMMIT="):
+        assert arg in text, f"CI no longer passes {arg} to the image build"
+
+
+@pytest.mark.parametrize("commit_epoch,expected", [
+    # Midnight, where a naive formatter drops the leading zeros and yields
+    # "2026.01.05.0" — rule 149 names this case specifically.
+    (datetime(2026, 1, 5, 0, 0, tzinfo=timezone.utc), "2026.01.05.0000"),
+    (datetime(2026, 1, 5, 0, 7, tzinfo=timezone.utc), "2026.01.05.0007"),
+    (datetime(2026, 12, 31, 23, 59, tzinfo=timezone.utc), "2026.12.31.2359"),
+    (datetime(2026, 8, 31, 4, 3, tzinfo=timezone.utc), "2026.08.31.0403"),
+])
+def test_the_name_format_zero_pads_every_field(commit_epoch, expected):
+    """`date -u +%Y.%m.%d.%H%M` is what CI runs; this pins what that must
+    produce, so a reformat that loses zero-padding fails here rather than in
+    a comparison months later."""
+    assert commit_epoch.strftime("%Y.%m.%d.%H%M") == expected
+    assert NAME_RE.match(expected)

tests/test_version_readout.py

@@ -0,0 +1,86 @@
+"""The app must SAY what it is running, and must not lie when it cannot find out.
+
+There is no frontend test runner in this repo, so these are source-inspection
+guards in the unit lane — the same idiom `check_plugin.py` uses on the hook
+shells. They are deliberately few and deliberately about ONE property each,
+because a grep-shaped test that asserts a whole file's contents fails on every
+refactor and gets deleted.
+
+WHY THIS FILE EXISTS. #3298: with a deploy misbehaving, nothing on the instance
+could say which commit was serving it, and the one endpoint whose job that is
+answered with the name of a branch. The value was fixed then. This is the other
+half — the value reaching a person — and #3127 checklist 12 is specific about
+the way it goes wrong: *never let a blank stand in for `unknown`*. A readout
+that renders a plausible value it never received is worse than one that renders
+nothing, because it ends the investigation instead of starting it.
+"""
+from __future__ import annotations
+
+import re
+from pathlib import Path
+
+FRONTEND = Path(__file__).resolve().parents[1] / "frontend" / "src"
+
+
+def test_something_actually_reads_the_version_endpoint():
+    """The endpoint is not enough; something must ask it.
+
+    `/api/version` answered correctly for weeks with no caller — an endpoint
+    reachable only by someone who already knew to curl it. Rule 27: a
+    capability with no surface the operator can touch is not shipped.
+    """
+    hits = [p for p in FRONTEND.rglob("*.ts") if "/api/version" in p.read_text()]
+    assert hits, "nothing under frontend/src fetches /api/version"
+
+
+def test_the_footer_does_not_default_to_a_plausible_version():
+    """The regression this readout was built to remove.
+
+    `appVersion` used to start life as the literal `"dev"` and the fetch
+    swallowed its own failure, so an instance that could not answer rendered
+    exactly what a healthy local build renders. Two very different states, one
+    string, and no way to tell them apart from the page.
+
+    Pinned as "the ref does not start at a version-shaped literal" rather than
+    as an exact initialiser, so a later refactor can change how the state is
+    held without failing here — what must not come back is the plausible
+    default.
+    """
+    app = (FRONTEND / "App.vue").read_text()
+    match = re.search(r"const appVersion = ref[^;]*;", app)
+    assert match, "App.vue no longer declares appVersion — update this guard"
+    decl = match.group(0)
+    assert '"dev"' not in decl and "'dev'" not in decl, (
+        f"appVersion defaults to a version-shaped literal: {decl}\n"
+        "A failed fetch would render as a real-looking version (#3127 "
+        "checklist 12). Start from a not-answered-yet value instead."
+    )
+
+
+def test_optional_version_fields_are_read_by_absence_not_falsiness():
+    """`build` is a number and 0 is a legitimate ordering key.
+
+    The payload omits what it does not know rather than sending `""` or `0`, so
+    the renderer's job is to distinguish ABSENT from present. `||` cannot: it
+    would report a real `build` of 0 as unknown, and it is the form a person
+    reaches for by habit. `??` is the correct one, which is why this pins the
+    operator rather than the rendered output.
+    """
+    view = (FRONTEND / "views" / "SettingsView.vue").read_text()
+    for field in ("channel", "build"):
+        assert f'versionInfo.{field} ?? "unknown"' in view, (
+            f"the {field} readout must use `?? \"unknown\"`, never `|| \"unknown\"` — "
+            "an absent field and a falsy one are different answers"
+        )
+
+
+def test_the_version_request_carries_a_deadline():
+    """Rule 156. A wait with no deadline cannot report that it failed.
+
+    This readout is consulted when an instance is misbehaving, which is exactly
+    when it may never answer. Without a deadline the surface sits on "still
+    loading" forever — the blank standing in for `unknown` again, arrived at
+    from the other direction.
+    """
+    src = (FRONTEND / "api" / "version.ts").read_text()
+    assert "timeoutMs" in src, "the version fetch must pass a deadline"

tests/test_write_path_trigger.py

@@ -25,7 +25,13 @@ def _snippet_item(nid, title, user_id=1):
 
 
 def _cfg(**over):
-    base = {"enabled": True, "threshold": 0.68, "top_k": 3}
+    # `rule_threshold` is the standing-rule arm's own bar (milestone 333 step
+    # 4). It belongs in the stand-in even though most tests here never reach
+    # that arm: the arm reads it while BUILDING its search arguments, so a
+    # missing key raises inside its fail-open except and turns the arm into a
+    # silent no-op — which is indistinguishable from it working and finding
+    # nothing.
+    base = {"enabled": True, "threshold": 0.68, "top_k": 3, "rule_threshold": 0.72}
     base.update(over)
     return base
 
@@ -354,10 +360,18 @@ async def test_telemetry_uses_its_own_source():
          patch.object(pc, "record_retrieval", rec), \
          patch.object(pc, "owner_names_for", AsyncMock(return_value={})):
         await pc.build_write_path_hint(1, "src/x.py", code=REAL_CODE, project_id=4)
-    rec.assert_called_once()
-    assert rec.call_args.kwargs["source"] == "write_path"
-    assert rec.call_args.kwargs["source"] != "auto_inject"
-    assert rec.call_args.kwargs["project_id"] == 4
+    sources = [c.kwargs["source"] for c in rec.call_args_list]
+    assert sources.count("write_path") == 1, sources
+    assert "auto_inject" not in sources
+
+    note_arm = next(c for c in rec.call_args_list if c.kwargs["source"] == "write_path")
+    assert note_arm.kwargs["project_id"] == 4
+
+    # The rule arm rides along on the same hint and logs its own call even when
+    # it finds nothing (#3497). This assertion used to be `assert_called_once`,
+    # which passed only because that row was never written — the test encoded
+    # the defect. The second row is the point of having two sources.
+    assert "write_path_rule" in sources, sources
 
 
 @pytest.mark.asyncio
@@ -426,6 +440,74 @@ async def test_writepath_threshold_is_operator_tunable_and_clamped():
     assert (await _cfg_with("banana"))["threshold"] == pc.WRITEPATH_DEFAULT_THRESHOLD
 
 
+@pytest.mark.asyncio
+async def test_the_rule_arm_has_its_own_tunable_bar():
+    """Rule #25 again, for the THIRD corpus (milestone 333 step 4).
+
+    Separate from the code threshold above and separately settable, because the
+    two are measured against different things: 0.68 was derived from code
+    against note PROSE (#2223), and rules are short imperative technical
+    English — a more homogeneous corpus whose noise floor sits higher.
+    """
+    from scribe.services import plugin_context as pc
+
+    async def _cfg_with(raw):
+        stored = {pc.RULEHINT_THRESHOLD_KEY: raw}
+        with patch.object(pc, "get_setting",
+                          AsyncMock(side_effect=lambda uid, k, d: stored.get(k, d))):
+            return await pc.get_writepath_config(1)
+
+    assert (await _cfg_with("0.8"))["rule_threshold"] == 0.8
+    assert (await _cfg_with("5"))["rule_threshold"] == 1.0
+    assert (await _cfg_with("-3"))["rule_threshold"] == 0.0
+    # Garbage falls back to the default, not to 0.0 — which on THIS arm would
+    # attach a standing rule to every write in the session.
+    assert (await _cfg_with("banana"))["rule_threshold"] == pc.RULEHINT_DEFAULT_THRESHOLD
+
+
+@pytest.mark.asyncio
+async def test_the_two_write_path_bars_are_independent():
+    """The split, asserted. Setting one must not move the other — the failure
+    that would silently undo this step is a config assembler that reads one key
+    into both fields."""
+    from scribe.services import plugin_context as pc
+
+    stored = {pc.WRITEPATH_THRESHOLD_KEY: "0.90", pc.RULEHINT_THRESHOLD_KEY: "0.61"}
+    with patch.object(pc, "get_setting",
+                      AsyncMock(side_effect=lambda uid, k, d: stored.get(k, d))):
+        cfg = await pc.get_writepath_config(1)
+
+    assert cfg["threshold"] == 0.90
+    assert cfg["rule_threshold"] == 0.61
+
+
+def test_the_rule_bar_defaults_above_the_code_bar():
+    """Not a number check — a DIRECTION check, and the only part of the default
+    that is defensible without one instance's histogram (rule 115).
+
+    The eligible rule corpus is orders of magnitude smaller than the note
+    corpus, so a top-k over it always returns something and a bar calibrated
+    for best-of-thousands is cleared by best-of-forty as arithmetic. Rules are
+    also more homogeneous than note prose, so their noise floor is higher. Both
+    facts point the same way: this bar must sit ABOVE the one it inherited.
+
+    Pinned as an inequality so tuning the value stays free while inverting the
+    relationship — which would silently reinstate #3311 — does not.
+    """
+    from scribe.services import plugin_context as pc
+
+    assert pc.RULEHINT_DEFAULT_THRESHOLD > pc.WRITEPATH_DEFAULT_THRESHOLD
+
+
+def test_the_rule_arm_asks_for_one_rule_not_two():
+    """With a corpus this small, top-k does as much damage as the threshold:
+    k=2 over a few dozen candidates means the second line is almost always the
+    second-best noise, carrying the same confident framing as the first."""
+    from scribe.services import plugin_context as pc
+
+    assert pc.RULEHINT_LIMIT == 1
+
+
 # --- the minimum-substance floor on the semantic arm (#2223) ------------------
 
 @pytest.mark.asyncio
@@ -867,14 +949,6 @@ def test_hook_skips_prose_and_data_files():
     assert '/scribe_defs.sh"' in src                   # sourced, not copied
 
 
-def test_plugin_version_bumped_with_the_hook():
-    """The #1040 lesson: a plugin change clients can't see is a change that didn't
-    ship."""
-    manifest = json.loads((PLUGIN / ".claude-plugin" / "plugin.json").read_text())
-    version = tuple(int(p) for p in manifest["version"].split("."))
-    assert version >= (0, 1, 31)
-
-
 def test_hook_keeps_sync_and_reuse_dedup_apart():
     """#2708's dedup audit, pinned: the hook holds TWO per-session id files and
     feeds each its own class — sync ids (snippets recording the edited file) to
@@ -1452,3 +1526,84 @@ def test_hook_keeps_the_rule_channel_apart_from_the_other_three():
     assert "(.rule_ids // [])[]?" in src            # its own write-back
     # And it rides the same request as the rest, not a second round trip.
     assert "${rule_exclude_q}" in src
+
+
+# ── `best_available` describes the BAR, not this arm's own second filter ──────
+#
+# #3739 fixed the rule arms: a record the reader had already been shown was
+# being logged as something the ranker turned away, which made the near-miss
+# distribution report scores ABOVE the very threshold it is read against.
+#
+# The fix keyed on `suppressed_count`, and its NULL branch was justified by
+# "null means the caller passed its exclusions INTO the search, so the reported
+# score is already post-exclusion". That is true of auto_inject and reuse_slot.
+# It is NOT true here: this is the one note arm that filters twice. `exclude_ids`
+# takes `seen - pulled_seen` into the search, but the pulled-and-seen ids stay in
+# the query on purpose (the arm's query doubles as the resemblance test) and are
+# dropped afterwards in Python.
+#
+# Live proof, on the first read after that fix shipped: write_path's near-miss
+# max was 0.822 while the lowest score it ever RETURNED was 0.6857 — a
+# "rejection" that beat every acceptance.
+
+
+def _search_reporting(score, note):
+    """A stand-in search that fills `report` the way the real one does.
+
+    It ignores `exclude_ids`, which is exactly the condition being reproduced:
+    a record that is in `seen` comes back from the search anyway. In production
+    that happens because `pulled_seen` is deliberately left in the query; here
+    it needs no ledger, and the arm's handling is the same either way.
+    """
+    async def _search(uid, q, **kw):
+        report = kw.get("report")
+        if report is not None:
+            report["best_available_score"] = score
+        return [(score, note)]
+    return _search
+
+
+async def _write_path_row(rec, **kwargs):
+    from scribe.services import plugin_context as pc
+    with patch.object(pc, "get_writepath_config", AsyncMock(return_value=_cfg())), \
+         patch.object(pc.snippets_svc, "list_snippets", AsyncMock(return_value=([], 0))), \
+         patch.object(pc, "record_retrieval", rec), \
+         patch.object(pc, "owner_names_for", AsyncMock(return_value={})), \
+         patch.object(pc, "semantic_search_notes",
+                      _search_reporting(0.9, fake_note(
+                          id=7, title="scored", user_id=1, note_type="snippet"))):
+        await pc.build_write_path_hint(1, "src/x.py", code=REAL_CODE, **kwargs)
+    return next(c for c in rec.call_args_list
+                if c.kwargs["source"] == "write_path")
+
+
+@pytest.mark.asyncio
+async def test_a_record_this_arm_withheld_itself_is_not_a_near_miss():
+    """The defect: the row's count is POST this arm's filter and the score was
+    captured PRE it, so a withheld record is indistinguishable from one the bar
+    rejected — while scoring higher than anything the bar ever let through."""
+    rec = MagicMock()
+    row = await _write_path_row(rec, exclude_ids=[7])
+
+    assert row.kwargs["results"] == [], "the hit was withheld, so nothing shown"
+    assert row.kwargs["best_available"] is None, (
+        "a 0.9 record this arm withheld itself was reported as the best thing "
+        "the THRESHOLD turned away. It would read as a bar set far too high "
+        "when the bar never rejected it at all (#3739)"
+    )
+
+
+@pytest.mark.asyncio
+async def test_a_call_that_withheld_nothing_still_reports_what_the_bar_refused():
+    """The other half, and what stops the fix being 'never report it'.
+
+    Without this, setting `best_available=None` unconditionally passes the test
+    above while deleting the measurement #3670 was built for.
+    """
+    rec = MagicMock()
+    row = await _write_path_row(rec)
+
+    assert row.kwargs["best_available"] == 0.9, (
+        "nothing was withheld here, so the reported score describes the bar "
+        "and must survive"
+    )