docs(6209): forge, dedup, tuning, registry, reply shapes and discipline, checkpoint, lesson kind tests

Eight more test files state their properties without issue, milestone,
rule and decision numbers. The tuning and suspension notes describe the
symptom a shipped default or a late ledger produces instead of one
install's dated readings; the reply-discipline and checkpoint docstrings
state the failure they prevent instead of the session that measured it.
test_empty_selector_is_the_rule_115_baseline is renamed for what it
checks: the no-forge baseline.

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

tests/test_pre_act_checkpoint.py

@@ -1,13 +1,12 @@
-"""A rule put IN FRONT of an act, not beside its result (#4214, milestone 419).
+"""A rule put IN FRONT of an act, not beside its result.
 
 WHY THIS EXISTS
 
 Every other rule surface in this plugin returns `additionalContext`, which
 Claude Code delivers alongside the tool RESULT. By the time the line is read
 the call is written, so the rule reads as commentary on a decision already
-made. Milestone 419 measured the cost over one session: seven misses, three
-caught by the operator and none by this system, five of them the same move —
-acting on the thing in hand without reading the contract around it.
+made — and the common miss is acting on the thing in hand without reading
+the contract around it.
 
 A checkpoint spends the same retrieval differently. The hook returns a `deny`,
 the act does not run, and the rule's own text can be read before the call
@@ -22,11 +21,10 @@ itself (a tuning value, and a test asserting 0.80 would fail on every retune
 while proving nothing) or the wording of the reason (prose, and it will be
 rewritten). The cases below express scores relative to the constant.
 
-THE ONE BOUNDARY THAT IS A RECORDED DECISION, NOT A DESIGN CHOICE. Only the
+THE ONE BOUNDARY THAT IS A STANDING DECISION, NOT A DESIGN CHOICE. Only the
 ACTION arm can hold. `scribe_prior_art.sh` carries a tested property that it
-never returns a permissionDecision — the operator's decision that a recall aid
-may not stand in the way of a write — and this milestone does not get to
-quietly overturn it. The write-path arm computes the same block and returns
+never returns a permissionDecision — a recall aid may not stand in the way of
+a write — and a checkpoint does not get to quietly overturn that. The write-path arm computes the same block and returns
 it, so the decision can be revisited with evidence; the hook ignores it. The
 last test here asserts that boundary holds, because it is exactly the kind of
 property that erodes when someone extends the feature later.
@@ -101,7 +99,7 @@ def test_a_preference_never_holds_an_act():
 
 def test_a_rule_the_session_already_opened_never_holds_an_act():
     """`held` is observable — a PostToolUse hook watches for the `get_rule`
-    call (#4100) — so this is a recorded event, not a model's self-report
+    call — so this is a recorded event, not a model's self-report
     about its own context. A session that read the rule has already had the
     thing the checkpoint exists to produce, and holding it again would punish
     the behaviour being asked for."""
@@ -167,7 +165,7 @@ def test_a_rule_with_no_trigger_renders_without_an_empty_bracket():
 def test_every_held_act_carries_a_rendered_reason():
     """Rendered at the one call site inside `checkpoint_for`, never by each
     arm: two arms that each remember to render it are two arms that can stop
-    agreeing on what a stop says, which is #3497's history for this pair."""
+    agreeing on what a stop says."""
     assert hold([hit(0.99, 1)])["reason"].strip()
 
 
@@ -253,8 +251,8 @@ def test_only_the_action_hook_can_hold_an_act():
     than left to memory.
 
     `scribe_prior_art.sh` runs before every Write and Edit and has never been
-    able to stop one. That is the operator's decision — a recall aid may not
-    stand in the way of the work — and `test_hook_never_returns_a_permission_
+    able to stop one. That is a standing decision — a recall aid may not stand
+    in the way of the work — and `test_hook_never_returns_a_permission_
     decision` in test_write_path_trigger.py holds the other half of it.
 
     This milestone has a live argument for extending the checkpoint to writes:
@@ -273,7 +271,7 @@ def test_only_the_action_hook_can_hold_an_act():
 
 
 def test_the_action_hook_caps_every_hold_it_emits():
-    """Structural, and able to fail (rule 167): the deny and the ledger call
+    """Structural, and able to fail: the deny and the ledger call
     must appear together. A deny emitted outside the guard is a session that
     can be held by the same rule on every command, which is the one outcome
     both guards exist to prevent."""