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>

tests/test_integration_shape_classify.py

@@ -169,6 +169,38 @@ async def test_rule_form_sweeps_unclassified_rows_only_and_applies_whole(seeded)
         await classify_shapes_where(other, pid, path="src", status="exempt", reason="x")
 
 
+@pytest.mark.integration
+async def test_sync_stamps_scoped_rows_and_unstamps_when_they_become_reachable(seeded):
+    """#2869: by-construction one-offs arrive `scoped` (mechanical), count as
+    accounted, are reached by the sweep's default, and go back to the todo
+    if a later tree makes them ordinary. A judgment overrides the stamp."""
+    from scribe.services.coverage import ArchiveShape
+    owner, pid, sid = seeded["owner"], seeded["pid"], seeded["snippet"]
+    scoped_shapes = [
+        ArchiveShape("web/Card.vue", "css", "card", ".card {", "s1", ".card { x: 1 }", True),
+        ArchiveShape("web/Card.vue", "sym", "load", "function load() {", "s2", "function load() {}", True),
+        ArchiveShape("src/util.py", "sym", "helper", "def helper():", "s3", "def helper(): pass", False),
+    ]
+    await sync_repo_shapes(pid, REPO, scoped_shapes, seen_marker="main")
+    rows, _ = await list_project_shapes(owner, pid, path="web/Card.vue")
+    assert {r.status for r in rows} == {"scoped"}
+    assert all(r.classified_by == "mechanical" and "by construction" in (r.reason or "") for r in rows)
+    # The human todo excludes them; the sweep's default still reaches them.
+    assert (await list_project_shapes(owner, pid, status="unclassified", path="web/Card.vue"))[1] == 0
+    out = await classify_shapes_where(
+        owner, pid, path="web/Card.vue", status="instance", snippet_id=sid, kind="css",
+    )
+    assert out["classified"] == 1
+    # Re-synced as ordinary: the stamped sym returns to the todo; the
+    # judged css keeps its judgment.
+    plain = [ArchiveShape(s.path, s.kind, s.name, s.signature, s.body_sha, s.body, False) for s in scoped_shapes]
+    await sync_repo_shapes(pid, REPO, plain, seen_marker="main")
+    rows, _ = await list_project_shapes(owner, pid, path="web/Card.vue")
+    by_symbol = {r.symbol: r for r in rows}
+    assert by_symbol["load"].status == "unclassified" and by_symbol["load"].classified_by is None
+    assert by_symbol["card"].status == "instance" and by_symbol["card"].snippet_id == sid
+
+
 @pytest.mark.integration
 async def test_list_filters_compose(seeded):
     owner, pid, sid = seeded["owner"], seeded["pid"], seeded["snippet"]