docs(6209): test prose in the present tense — "used to", "previously", "before this" restated as the failure shape

Twenty-eight test files described the code they guard by what it did
before a fix. Each is now the property and the failure it prevents, in the
present tense: the backfill snapshot, the per-dial calibration query, the
rule scope, the lesson trigger filter, the subshell global, the trash owner
scope, the version readout fallback, and others. A docstring line that
narrated the backup suite's own history is removed.

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

tests/test_services_trash.py

@@ -124,8 +124,8 @@ async def test_purge_expired_deletes_across_models_when_positive():
 
 
 def test_owner_clause_scopes_every_model():
-    """Regression: every trash op must owner-scope, including topics/rules
-    which previously had NO owner check (IDOR across tenants)."""
+    """Every trash op must owner-scope, topics and rules included — a model
+    with no owner check is an IDOR across tenants."""
     from scribe.services.trash import _owner_clause, _MODEL_FOR
     from scribe.models.note import Note
     from scribe.models.rulebook import Rulebook, RulebookTopic, Rule