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/services/coverage.py

@@ -107,6 +107,7 @@ class Definition(NamedTuple):
     signature: str
     body_sha: str
     body: str
+    line: int = -1   # 0-based line the definition starts on (#2869)
 
 
 def _definition_on(raw: str) -> tuple[str, str] | None:
@@ -186,11 +187,47 @@ def extract_definitions(text: str) -> list[Definition]:
         block = lines[i:end]
         out.append(Definition(
             kind, name, lines[i].strip()[:_SIGNATURE_CAP], _block_sha(block),
-            "\n".join(block),
+            "\n".join(block), i,
         ))
     return out
 
 
+# --- by-construction scope (#2869) -------------------------------------------
+#
+# A Vue single-file component's `<style scoped>` rules and its `<script setup>`
+# functions cannot be reached from any other file: they are one-offs by
+# construction, not by judgment. The sync stamps them `scoped` (mechanical) so
+# the human todo holds only shapes a person should look at, while the bodies
+# stay in play for the proposer, derive grouping and divergence — the five
+# auth views' identical rules were found exactly there. Unscoped `<style>` in
+# a .vue and every non-.vue file stay ordinary.
+_STYLE_OPEN_RE = re.compile(r"^\s*<style\b[^>]*\bscoped\b", re.IGNORECASE)
+_STYLE_CLOSE_RE = re.compile(r"^\s*</style\s*>", re.IGNORECASE)
+
+
+def scoped_definitions(path: str, text: str, defs: list[Definition]) -> set[tuple[str, str]]:
+    """The (kind, name) pairs among ``defs`` that are one-offs by
+    construction in this file: every sym in a .vue, and every css rule
+    that starts inside a `<style scoped>` block. Empty for other files."""
+    if not (path or "").lower().endswith(".vue"):
+        return set()
+    ranges: list[tuple[int, int]] = []
+    open_at: int | None = None
+    for i, ln in enumerate(text.splitlines()):
+        if open_at is None and _STYLE_OPEN_RE.match(ln):
+            open_at = i
+        elif open_at is not None and _STYLE_CLOSE_RE.match(ln):
+            ranges.append((open_at, i))
+            open_at = None
+    out: set[tuple[str, str]] = set()
+    for d in defs:
+        if d.kind == "sym":
+            out.add((d.kind, d.name))
+        elif any(a <= d.line <= b for a, b in ranges):
+            out.add((d.kind, d.name))
+    return out
+
+
 def extract_shapes(text: str) -> list[tuple[str, str]]:
     """Every (kind, name) this text DEFINES — kind is "css" or "sym".
 
@@ -220,6 +257,7 @@ class ArchiveShape(NamedTuple):
     signature: str
     body_sha: str
     body: str
+    scoped: bool = False   # one-off by construction (#2869)
 
 
 def shapes_from_archive(blob: bytes) -> list[tuple[str, str, str]]:
@@ -250,9 +288,14 @@ def definitions_from_archive(blob: bytes) -> list[ArchiveShape]:
                 text = handle.read().decode("utf-8")
             except UnicodeDecodeError:
                 continue
+            defs = extract_definitions(text)
+            scoped = scoped_definitions(path, text, defs)
             shapes.extend(
-                ArchiveShape(path, d.kind, d.name, d.signature, d.body_sha, d.body)
-                for d in extract_definitions(text)
+                ArchiveShape(
+                    path, d.kind, d.name, d.signature, d.body_sha, d.body,
+                    (d.kind, d.name) in scoped,
+                )
+                for d in defs
             )
     return shapes
 
@@ -414,7 +457,7 @@ async def compute_coverage(
     # repo that was unreachable today still has live rows, and they count.
     rows = await shape_ledger.live_rows(project_id)
     counts = {"canonical": 0, "instance": 0, "variant": 0, "exempt": 0,
-              "unclassified": 0}
+              "scoped": 0, "unclassified": 0}
     for row in rows:
         counts[row.status] = counts.get(row.status, 0) + 1
     by_repo: dict[str, dict[str, int]] = {}
@@ -571,7 +614,7 @@ def coverage_line(coverage: dict) -> str:
     counts = coverage.get("counts") or {}
     breakdown = " · ".join(
         f"{counts[k]} {k}"
-        for k in ("canonical", "instance", "variant", "exempt")
+        for k in ("canonical", "instance", "variant", "exempt", "scoped")
         if counts.get(k)
     )
     line = (