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_moment_mappings.py

@@ -1,4 +1,4 @@
-"""Real-Postgres tests for an install's moment mappings (milestone 458 step 2).
+"""Real-Postgres tests for an install's moment mappings.
 
 What these pin is what the in-session correction promises the operator: a
 mapping made is in force on the next call, a default switched off stays off,