feat(shapes): the practice is written where it is read, and the coverage line measures the slip (milestone 439 step 6)

- reusing-code: "Before the turn ends — say what you built" — the four
  verdicts, the one classify_shapes(repo=…) call, and the component file as a
  shape. Description names the end-of-turn moment.
- shape-accounting: the writer judges; audits are the check that it held.
  The write path SUGGESTS (no more hook instances); component file rows and
  whole-file canon described; scoped covers Svelte too.
- _INSTRUCTIONS reuse line: "before the turn ends, say what you built
  (create_snippet the reusable, classify_shapes the rest)" — 1570/1600.
- Coverage line: "written-shape check (7d): N turns checked, M asked, K left
  unjudged", from the Stop hook's recorded outcomes; silent until the
  question has been put.
- test_guidance_ownership pins the new topic on reusing-code.
- prior-art hook header no longer says it stamps instance rows.

Plugin version minted.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/scribe/services/shape_check.py

@@ -27,6 +27,9 @@ report_check gives.
 from __future__ import annotations
 
 import json
+from datetime import datetime, timedelta, timezone
+
+from sqlalchemy import select
 
 from scribe.models import async_session
 from scribe.models.app_log import AppLog
@@ -145,3 +148,45 @@ def parse_written(raw: str, *, cap: int = 200) -> list[tuple[str, str, str]]:
         if len(out) >= cap:
             break
     return out
+
+
+# The window the coverage line reports the write-time figure over. A week is
+# long enough to hold a few working sessions on a project and short enough
+# that a reflex that started slipping shows up while it is still news.
+WINDOW_DAYS = 7
+
+
+def summarise(outcomes: list[str]) -> dict:
+    """{checked, asked, left} from a list of recorded outcomes.
+
+    `checked` is turns the question was put to (a first stop that wrote
+    something): passed + blocked. `asked` is the blocked ones. `left` is
+    asks the agent walked past — the stop after a block that still had
+    unjudged shapes. That last number is the slip the milestone exists to
+    make visible."""
+    checked = sum(1 for o in outcomes if o in ("passed", "blocked"))
+    asked = sum(1 for o in outcomes if o == "blocked")
+    left = sum(1 for o in outcomes if o == "left_after_block")
+    return {"checked": checked, "asked": asked, "left": left}
+
+
+async def window_summary(project_id: int, *, days: int = WINDOW_DAYS) -> dict:
+    """The write-time figure for one project over the last ``days``."""
+    since = datetime.now(timezone.utc) - timedelta(days=days)
+    async with async_session() as session:
+        rows = (await session.execute(
+            select(AppLog.details).where(
+                AppLog.category == "plugin",
+                AppLog.action == "shape_check",
+                AppLog.created_at >= since,
+            )
+        )).scalars().all()
+    outcomes: list[str] = []
+    for raw in rows:
+        try:
+            details = json.loads(raw or "{}")
+        except (TypeError, ValueError):
+            continue
+        if details.get("project_id") == project_id:
+            outcomes.append(details.get("outcome") or "")
+    return {**summarise(outcomes), "days": days}