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_milestone_search.py

@@ -1,8 +1,7 @@
-"""Real-Postgres tests for finding a plan by meaning (milestone 415, steps 3 and 4).
+"""Real-Postgres tests for finding a plan by meaning.
 
-A project's roadmap written as milestones was invisible to recall: `search`
-covered notes, tasks and rules, so "is there already a plan for this?" had no
-tool. What a mock cannot show is the join scoping the vectors to a project and
+A project's roadmap is written as milestones, and `search` reaches them, so
+"is there already a plan for this?" has a tool. What a mock cannot show is the join scoping the vectors to a project and
 to what the caller may read, so these seed real milestones with hand-made
 vectors and stub only the embedder.
 """
@@ -84,7 +83,7 @@ async def test_a_project_the_caller_cannot_read_returns_nothing(roadmap):
     assert await _found(roadmap["stranger"]) == []
 
 
-# ── the plan gate (step 4): start_planning finds the plan before making another ──
+# ── the plan gate: start_planning finds the plan before making another ──
 
 LONG = "Resolve works and editions against the metadata providers. " * 5