feat(ledger): divergence readout — button B where button A is canon, shape history, and judged-shape recheck (#2793, milestone 294 step 7)

Every judgment now goes through one helper that remembers the fingerprint
judged (classified_sha) and writes a code_shape_events row; the sync writes
vanished / reappeared / drifted events and flags recheck_at when a body
moves under an instance/variant. The refresh flags diverges_from on shapes
new since the previous computation that sit where one canon dominates the
judged siblings of their directory+kind and were not proposed as that canon
(a first seed flags nothing); the write-path hint asks the same question
in-band for the shapes the hook names. list_shapes(flag=divergence|recheck),
shape_history(project_id, path, symbol) (read-only), coverage line/payload/
card carry divergent + recheck. Backup v8 carries the history. Plugin 0.1.36.

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

tests/test_pattern_coverage.py

@@ -507,3 +507,19 @@ def test_coverage_line_names_the_proposers_standing():
     assert "; 90 unclassified (40 proposed, 2 derive groups), largest: src" in line
     line = coverage_line({**base, "proposed": 0, "derive_groups": [{"group": "a"}]})
     assert "(1 derive group)" in line
+
+
+def test_coverage_line_names_divergence_and_recheck():
+    from scribe.services.coverage import coverage_line
+
+    base = {
+        "total": 100, "accounted": 40, "unclassified": 60,
+        "counts": {"canonical": 10, "instance": 30, "variant": 0, "exempt": 0},
+        "computed_at": "2026-08-21T00:00:00+00:00",
+        "largest_gaps": [{"dir": "src", "unclassified": 60, "total": 60}],
+    }
+    line = coverage_line({**base, "divergent": 2, "recheck": 1, "proposed": 5})
+    assert "; 60 unclassified (5 proposed, 2 DIVERGENT), largest: src" in line
+    assert line.endswith("; 1 judged shape changed since judged — recheck")
+    assert "DIVERGENT" not in coverage_line(base)
+    assert "recheck" not in coverage_line(base)