docs(6209): rulebooks, pull telemetry, lesson usage, duplicate arm, cited status, trigger shape

Six more test files state their pinned properties without the issue and
milestone history: the pull-telemetry guard explains enumerating kinds
instead of listing two getter incidents, cited-record status explains why
a hint's id needs its status instead of recounting one misreported step,
and the trigger-shape guard keeps its reasoning about why prose heuristics
fail while dropping the dated corpus audit.

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

tests/test_lesson_usage_surface.py

@@ -1,21 +1,18 @@
-"""A lesson's surfaced-vs-opened counts reach a reader (#4196).
+"""A lesson's surfaced-vs-opened counts reach a reader.
 
-The lesson slot has recorded usage since it shipped, and until this nothing
-showed it. `get_lesson`'s REST door attached it; the list did not, neither MCP
-door did, and no view rendered it — so the one kind whose central question is
-"is this trigger firing on the right situation" was the one kind whose answer
-was unreadable.
+Every door — the REST list and detail, both MCP doors, and the view — carries
+the counts, because the one kind whose central question is "is this trigger
+firing on the right situation" needs that answer readable.
 
-WHY THE COUNTS MATTER MORE HERE THAN ON A SNIPPET. #4196 asks whether a lesson
-repeatedly followed should become a rule, and names the trap: raw frequency
+WHY THE COUNTS MATTER MORE HERE THAN ON A SNIPPET. Whether a lesson repeatedly
+followed should become a rule has a trap: raw frequency
 cannot tell "this should bind" from "this trigger is too broad", which is the
 commoner reading. Surfaced-AND-opened can. Neither question is answerable by
 anything that cannot see the numbers, which is why this is the first step and
 not the threshold.
 
-NO THRESHOLD IS ASSERTED ANYWHERE HERE, deliberately. At the time of writing
-the corpus is 10 lessons with 7 recorded surfacings and 3 opens; a promotion
-rule fitted to that would be fitting noise, and `UsageBadge` already declines
+NO THRESHOLD IS ASSERTED ANYWHERE HERE, deliberately. A promotion rule fitted
+to a small corpus would be fitting noise, and `UsageBadge` already declines
 to render a verdict on fewer than three surfacings for the same reason.
 """
 import inspect
@@ -115,11 +112,10 @@ async def test_get_lesson_reads_the_count_before_recording_its_own_pull():
     assert out["usage"]["pull_count"] == 1
 
 
-# ── the REST door, on structure (rule 167) ───────────────────────────────────
+# ── the REST door, on structure ──────────────────────────────────────────────
 #
-# MOVED 2026-09-21 (#4230), not weakened. These used to look for
-# `usage_for_notes(` and `empty_usage()` in the route body. Both now live in
-# ONE seam, `note_usage.attach_usage`, which seven doors share — so the
+# `usage_for_notes(` and `empty_usage()` live in ONE seam,
+# `note_usage.attach_usage`, which seven doors share — so the
 # zero-fill and the single aggregate are pinned once, against the seam, in
 # tests/test_usage_attach_seam.py. What stays HERE is what only this route can
 # get wrong: that it calls the seam at all, once, and before it records a pull.
@@ -166,7 +162,7 @@ def test_the_rest_detail_door_also_reads_before_it_records():
 
 
 def test_these_guards_can_fail():
-    """Rule 167: falsify the shape they assert against, so a guard that has
+    """Falsify the shape they assert against, so a guard that has
     quietly stopped describing anything cannot pass by describing nothing."""
     src = _route_source("list_lessons_route")
     assert "def list_lessons_route" in src
@@ -174,21 +170,21 @@ def test_these_guards_can_fail():
 
 
 def test_the_detail_view_renders_the_badge_rather_than_respelling_it():
-    """Snippet #3460: reach for UsageBadge and pass the kind's own advice; a
-    view's scoped re-spelling of `.usage-tag` is what that component replaced.
+    """Reach for UsageBadge and pass the kind's own advice; a view's scoped
+    re-spelling of `.usage-tag` is what that component exists to prevent.
 
     The advice is the kind-specific half. For a lesson it points at the
     trigger, not at deletion — a lesson nobody opens is usually keyed to a
     situation nobody is in, which is `update_lesson`'s own words and the
-    reading #4196 calls the commoner one.
+    commoner reading.
     """
     view = (Path(__file__).resolve().parents[1]
             / "frontend/src/views/LessonDetailView.vue").read_text()
     assert "UsageBadge" in view
     assert "usage-tag" not in view, "re-spelled the chip instead of reusing it"
 
-    # The sentence moved out of this template into the shared table (#4230,
-    # recorded on #3460). Assert BOTH halves, so the guard cannot pass by the
+    # The sentence lives in the shared table, not this template. Assert BOTH
+    # halves, so the guard cannot pass by the
     # view pointing at an entry that no longer says the right thing.
     assert "DEAD_WEIGHT_ADVICE.lesson" in view, "the view no longer reads the lesson advice"
     table = (Path(__file__).resolve().parents[1]