docs(6209): seventeen more test files — lesson shape and round trip, rule scope/moments/kind/surfacing, drift, deadlock race, backup, inception, backfill, claims, supersession, ledgers, family shapes

Docstrings and comments state the property and its reason in the present
tense. The session-context ledger test no longer describes the decision it
"used to pin"; the supersession tests state demote-not-filter without the
quote; one-row measurements become the general shape with their figures.

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

tests/test_integration_rule_scope.py

@@ -1,4 +1,4 @@
-"""Real-Postgres tests for WHERE a rule reaches (milestone 414, step 1).
+"""Real-Postgres tests for WHERE a rule reaches.
 
 A rule lives in a rulebook topic (global) or on one project. Retrieval used to
 ignore that and search every rule the user owned, so each project's rules were
@@ -78,7 +78,7 @@ async def _found(user_id: int, **scope) -> set[int]:
     """The rule ids a search finds — and a failure, not an empty set, when the
     search never ran. `semantic_search_rules` fails open (an exception becomes
     []), so without `report["searched"]` an error and a scoping miss read the
-    same (#4958)."""
+    same."""
     report: dict = {}
     raised: list[str] = []
     with patch("scribe.services.embeddings.get_embedding",
@@ -109,7 +109,7 @@ async def test_retrieval_reaches_a_rule_only_from_its_home(homes):
 
 
 async def test_a_shared_project_brings_its_rules_to_a_collaborator(homes):
-    """Readability goes through access.can_read_project (rule 78): a viewer on
+    """Readability goes through access.can_read_project: a viewer on
     A gets A's rules. Not the owner's global rules — rulebooks are the
     owner's — and not B's, which is not shared."""
     collaborator = homes["collaborator"]
@@ -118,9 +118,9 @@ async def test_a_shared_project_brings_its_rules_to_a_collaborator(homes):
 
 
 async def test_an_in_scope_rule_is_found_however_many_closer_rules_are_out_of_scope():
-    """#4958. Ordered through the HNSW index, the search took the ~40 nearest
-    chunks from every owner and filtered them AFTERWARDS — so a reader's own
-    rule ranked past the 40th chunk overall was never returned. Here another
+    """A search ordered through the HNSW index takes the ~40 nearest chunks
+    from every owner, and filtering them AFTERWARDS loses a reader's own rule
+    ranked past the 40th chunk overall. Here another
     user's 80 rules all sit nearer the query than the reader's one rule; the
     reader's search must still find it."""
     tag = uuid.uuid4().hex[:8]