feat(shapes): a component file is a candidate shape in its own right (milestone 439 step 5)

A single-file component defines `.card`, `.title` and a `Props`, never
anything named after itself — so the ledger could not hold "StatusChip is
canon" and could not say a new card was built where one already existed.

- coverage.is_file_unit: a file that RENDERS (its markup names classes, or it
  opens a <script>/<template>/<style> block) and defines nothing named after
  its stem gets one `file` row. Structural, not a framework list: Svelte and
  Vue components qualify, a TSX component already has its function's row, a
  module is accounted for by its definitions. Emitting every file would have
  put every module of every project in the todo at once.
- No body fingerprint on file rows, so an edit never re-asks a judgment.
- `file` is its own form and family; derive grouping skips it (`index`,
  `+page` repeat by convention). Divergence buckets it on its own, so a new
  component where a component canon dominates is a fair question.
- mark_canonicals: a snippet recorded at a path with no symbol makes that
  file row canonical; it still covers no definition inside.
- The write hooks apply the same test before noting a new file for the
  end-of-turn question.

Plugin version minted.

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

tests/test_integration_shape_classify.py

@@ -1231,3 +1231,31 @@ async def test_unjudged_is_what_nobody_read(seeded):
     assert got[1]["evidence"]["stamped"] == {"snippet_id": sid, "score": 0.7}
     assert got[2]["evidence"] == {}
     assert await unjudged_shapes(pid, []) == []
+
+
+@pytest.mark.integration
+async def test_a_whole_file_snippet_makes_its_file_row_canonical(seeded):
+    """Milestone 439: a snippet recorded at a component's path, with no
+    symbol, is the canon for that file row — the claim a whole-file record
+    makes and a definition row never could. It still covers no definition
+    inside the file."""
+    from scribe.services import snippets as snippets_svc
+    from scribe.services.coverage import _recorded_locations
+    from scribe.services.shape_ledger import mark_canonicals
+
+    owner, pid = seeded["owner"], seeded["pid"]
+    await sync_repo_shapes(pid, REPO, SHAPES + [
+        ("web/lib/StatusChip.svelte", "file", "StatusChip"),
+        ("web/lib/StatusChip.svelte", "css", "chip"),
+    ], seen_marker="c1")
+    chip = await snippets_svc.create_snippet(
+        owner, name="StatusChip — the one status pill",
+        code="<span class=\"chip\">{label}</span>", language="svelte",
+        repo="Widget", path="web/lib/StatusChip.svelte", project_id=pid,
+    )
+    await mark_canonicals(pid, await _recorded_locations(owner, pid))
+    rows, _ = await list_project_shapes(owner, pid, path="web/lib/StatusChip.svelte")
+    by = {(r.kind, r.symbol): r for r in rows}
+    assert by[("file", "StatusChip")].status == "canonical"
+    assert by[("file", "StatusChip")].snippet_id == int(chip.id)
+    assert by[("css", "chip")].status == "unclassified"