docs(6209): forty test files — design cascade and stylesheet, embeddings, family canon, forge, backup round trips, inception, placement, platforms, moments, rule move and verification, search scope, facets

Module and test docstrings state what is pinned without the record number
or step that introduced it. Incident accounts become the failure shape in
the present tense: the pipefail head, the code_shapes import, the export
order, the facet dialects, the cross-kind repeat, the write-once kind.

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

tests/test_integration_family_adoption.py

@@ -1,4 +1,4 @@
-"""The adoption ledger against real Postgres (milestone 463 step 4).
+"""The adoption ledger against real Postgres.
 
 What the unit lane can't show: an answer moves the row and logs exactly one
 decision; an owed answer files its task in the OWING project, tagged to the
@@ -236,7 +236,7 @@ async def test_another_projects_answer_is_recorded_as_precedent(family):
     assert first["decision"]["id"] in second["decision"]["precedent_ids"]
     assert second["precedents"][0]["relation"] == "same idea, another project"
     assert second["precedents"][0]["project_title"] == "android one"
-    # A precedent says its reason once: before/after are state only (#5131).
+    # A precedent says its reason once: before/after are state only.
     assert second["precedents"][0]["reason"] == "the source app"
     assert "reason" not in second["precedents"][0]["after"]
 
@@ -392,7 +392,7 @@ async def test_the_matrix_hides_what_the_caller_cannot_read(family):
     assert all(i["note_id"] != family["note"] for i in matrix["ideas"])
 
 
-# --- the shape ledger as evidence (step 5) -------------------------------------------
+# --- the shape ledger as evidence ----------------------------------------------------
 
 REPO = "git.example/android-two"
 KOTLIN_BODY = (