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>

plugin/hooks/scribe_prior_art.sh

@@ -17,8 +17,9 @@
 # It is also the shape ledger's write-path feed (#2791): it names the
 # definitions being written (`shapes=`), and the server — only when the
 # session has PULLED a snippet this code references or resembles — records
-# them as instance rows, classified_by=hook. Evidence, not judgment; the
-# context line says what landed so a wrong stamp is corrected in the moment.
+# it as a PROPOSAL on them ("looks like #N"), never a status (milestone 439).
+# The agent's own end-of-turn judgment is the verdict; the same names go to
+# the written-shapes ledger the Stop hook asks about.
 #
 # NEVER BLOCKS. It returns `additionalContext` with no `permissionDecision`, so
 # the write proceeds untouched and Claude sees the note beside the tool result.
@@ -103,8 +104,8 @@ fi
 # changes the inside of a function rather than its signature — the definition
 # enclosing the edit, found by walking the target file upward from the edited
 # lines. The server decides whether evidence exists (the session pulled a
-# snippet this code references or resembles) and stamps instance rows; with
-# no pulled canon in play, nothing is recorded. Titles only still — this sends
+# snippet this code references or resembles) and records it as a proposal;
+# with no pulled canon in play, nothing is recorded. Titles only still — this sends
 # names, not bodies.
 # ---------------------------------------------------------------------------
 #