feat(ledger): the scoped bucket — by-construction one-offs are stamped by the sync, not judged by a person (#2869, milestone 294)

The 2026-08 audit left 77% of Scribe's ledger `exempt`, most of it a Vue
component's scoped <style> rules and <script setup> functions — one-offs by
construction (unreachable from any other file) that add nothing when judged
one by one and bury the rows a person should look at.

- coverage: Definition carries its line; scoped_definitions() names, per
  .vue file, every sym and every css rule inside <style scoped>; ArchiveShape
  carries the flag.
- sync: such rows are stamped status=scoped / classified_by=mechanical with
  the by-construction reason (history event recorded); un-stamped back to
  unclassified if a later tree makes them ordinary; a judgment overrides.
- The machine still sees them: proposer, derive grouping, divergence, hook
  evidence, canonical stamping and classify_shapes_by_rule's default all
  treat unclassified + scoped as the unjudged set (_MECHANICAL_TODO). Only
  the human todo (status=unclassified) and largest_gaps exclude them.
- accounting counts `scoped`; coverage line and the project card legend show
  it; SHAPE_STATUSES gains it (no DB CHECK on status — no migration).
- shape-accounting skill documents the bucket; plugin 0.1.37.

Operator decision on #2869 (2026-08-21): keep extracting everything, stamp
mechanically, keep `exempt` a human judgment.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/scribe/models/code_shape.py

@@ -16,8 +16,14 @@ from scribe.models import Base
 from scribe.models.base import TimestampMixin, iso
 
 # The classification vocabulary (note 2786). `unclassified` is the default and
-# THE todo state; every other status is a judgment, stamped with who made it.
-SHAPE_STATUSES = ("canonical", "instance", "variant", "exempt", "unclassified")
+# THE todo state; every other status is a judgment, stamped with who made it —
+# except `scoped` (#2869): the coverage sync's mechanical stamp on shapes that
+# are one-offs BY CONSTRUCTION (a Vue component's scoped <style> rules and its
+# <script setup> functions — unreachable from any other file). Scoped rows are
+# accounted for without a human judging them, so `exempt` keeps meaning "a
+# person looked"; the proposer, derive grouping and divergence still see them,
+# and any judgment (instance/variant/exempt) overrides the stamp.
+SHAPE_STATUSES = ("canonical", "instance", "variant", "exempt", "scoped", "unclassified")
 SHAPE_CLASSIFIERS = ("agent", "audit", "hook", "mechanical", "import")
 
 # How the mechanical proposer (#2792) arrived at a proposal, strongest first.