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_embedding_text.py

@@ -9,7 +9,7 @@ the dangerous one: a recurring task embedded to a different shape than the rest
 of the corpus is ranked against documents it doesn't match, and nothing reports
 it. A wrong vector returns results; it just returns the wrong ones.
 
-It is also the precondition for #2486. A dev-log's vector separates from five
+It is also the precondition for comparing document shapes. A dev-log's vector separates from five
 unrelated dev-logs by 0.023 where a snippet separates by 0.153, and the leading
 explanation is shape — a snippet states its purpose twice in a short document.
 Testing an alternative against three copies would mean testing a shape that
@@ -77,5 +77,5 @@ def test_nothing_else_builds_the_embedding_document_itself():
         f"these build the embedding document inline instead of calling "
         f"embedding_text(): {offenders}. One definition — an inlined copy is "
         f"ranked against a corpus it no longer matches the moment the shape "
-        f"changes, and nothing reports it (#2486)."
+        f"changes, and nothing reports it."
     )