docs(6209): the remaining test files — lessons, reply moment and shape, retrieval specs and scopes, rule doors and judgments, services, snippets, search scope; five tests renamed to their property

Docstrings, section headers and assertion messages drop the record number,
milestone or step that introduced the behaviour, and incident accounts are
restated as the present-tense failure shape. A dead pointer to a design doc
that is not in the repo is removed.

Renamed to the property they check:
  test_the_old_shape_would_be_caught -> test_a_rank_then_scope_query_is_caught
  test_a_ledger_repeat_no_longer_produces_that_case_at_all -> test_a_ledger_repeat_is_counted_not_withheld
  test_the_header_no_longer_promises_once_per_session -> test_the_header_explains_the_seen_marker
  test_the_portal_case_no_longer_stamps_one_canon_onto_a_whole_file -> test_one_canon_is_not_stamped_onto_a_whole_file
  test_the_repos_own_prose_no_longer_defines_with -> test_the_repos_own_prose_does_not_define_with
  test_the_original_regression_create_note_with_content -> test_the_real_server_refuses_content_on_create_note

Fixture and example ids stay: "note 5" in a supersession chain, "rule 156"
in an illustrative question, `#2275` as the hex-versus-citation case,
`#3244` as the example of a bare number, fixed dates in date-filter tests.

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

tests/test_services_project_summaries.py

@@ -1,10 +1,10 @@
-"""Batched project summaries (#2384).
+"""Batched project summaries.
 
-The bug was not wrong output — it was CONNECTION COUNT. A per-project summary
-opened its own session and then one more per milestone, and the route fanned
-that out with asyncio.gather. For 25 projects that asked for roughly 250
-checkouts against a pool of 15, so most waited out the 30-second timeout and
-every other route on the instance queued behind them:
+The property is CONNECTION COUNT, not output. A per-project summary that opens
+its own session and then one more per milestone, fanned out with
+asyncio.gather, asks 25 projects for roughly 250 checkouts against a pool of
+15, so most wait out the 30-second timeout and every other route on the
+instance queues behind them:
 
     QueuePool limit of size 5 overflow 10 reached, connection timed out
     GET /api/settings  500  30584.0ms
@@ -12,7 +12,7 @@ every other route on the instance queued behind them:
 
 So these tests assert the number of sessions opened, not only the values
 returned. A version that produced identical output while opening a session per
-project would pass a correctness test and reproduce the outage.
+project would pass a correctness test and exhaust the pool.
 """
 from datetime import datetime, timezone
 from unittest.mock import AsyncMock, MagicMock, patch
@@ -118,7 +118,7 @@ async def test_milestone_summaries_for_many_projects_open_ONE_session():
 
     assert opened[0] == 1
     # Touched is the later of the milestone's own edit and its newest step
-    # update (#4045): steps closing today count, an old step doesn't pull it back.
+    # update: steps closing today count, an old step doesn't pull it back.
     assert out[1][0]["last_touched_at"] == step_closed.isoformat()
     assert out[2][0]["last_touched_at"] == written.isoformat()
     assert out[1][0]["completed"] == 2 and out[1][0]["total"] == 3