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_rule_usage_wiring.py

@@ -446,9 +446,9 @@ async def test_the_prompt_arm_retrieves_against_what_the_operator_SAID():
     Both other arms are keyed on an act — a file write, a command. A rule that
     governs what to SAY has no act in front of it: extract intent from loose
     phrasing, raise a conflict before acting, end a finding with an offer all
-    bind on a response. Before this, the operator's message reached only
-    `semantic_search_notes`, so no rule had ever been retrieved against a
-    thing the operator actually said.
+    bind on a response. If the operator's message reached only
+    `semantic_search_notes`, no rule would ever be retrieved against a thing
+    the operator actually said.
     """
     rec = MagicMock()
     search = AsyncMock(return_value=[(0.79, fake_rule(