feat(rules): the write path can notice a standing rule it was never given (#3031, milestone 307 step 5, hook arm)

A conditional rule is not resident, so a session can be about to violate one it
was never handed. This arm notices: when what is being written resembles a
rule's trigger, the hint names it and says to read it before deciding it does
not apply.

A SUGGESTION, and the plan was wrong about why it could be more. It claimed the
hook "already resolves a path to an area" — it does not, and nothing in Scribe
maps a path to a System or a canonical area (build_write_path_hint resolves
paths against snippet LOCATIONS, a different index; the learned-alias idea
belongs to another project). Correction logged on the task. Rather than invent
path→area inference to make a stale claim true, the arm does what D7 already
decided and what this surface already IS: tags bind at enter_project, meaning
suggests here. The header of the hook says NEVER BLOCKS; dressing a hint up as
binding would have been the actual mistake.

CONDITIONAL RULES ONLY. An always-on rule is already in the session, so
re-offering it is noise — and noise on a hint that fires on every write is how
a hint gets ignored.

Telemetry goes to retrieval_logs, NOT note_usage_events, and that is a
correctness call rather than a preference: note_usage ids are REMAPPED on a
backup restore, so a rule id written there would come back attached to whatever
note took that number — silently corrupting the evidence the next true-up is
supposed to read. retrieval_logs is never restored and `source` already
separates surfaces. record_retrieval's `results` type widened to match what it
actually needs (an `.id`), instead of passing a Rule to something annotated Note.

The rule dedup gets its OWN state file and query parameter, like the three
channels before it — #2708's lesson was that one shared channel lets a hint of
one class silence a different class that had never been shown. Plugin version
bumped: a hook change clients cannot see did not ship (#1040).

The stub is autouse in conftest rather than added to forty-odd call sites: the
arm loads an embedding model, and every existing test that stubs the NOTES
search would otherwise pull a real model in through the one arm it had no way
to know about.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

src/scribe/services/embeddings.py

@@ -711,6 +711,7 @@ async def semantic_search_rules(
     query: str,
     limit: int = 5,
     threshold: float = _SIMILARITY_THRESHOLD,
+    tier: str | None = None,
 ) -> list[tuple[float, "Rule"]]:
     """Return up to *limit* (score, rule) pairs most relevant to *query*.
 
@@ -721,6 +722,11 @@ 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.
+
     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.
 
@@ -757,6 +763,7 @@ async def semantic_search_rules(
                         Rulebook.owner_user_id == user_id,
                         Project.user_id == user_id,
                     ),
+                    *( [Rule.tier == tier] if tier else [] ),
                 )
                 # Overfetch so collapsing chunks to their best row still fills
                 # the page — the same reason the note search overfetches.