docs(6209): wide net, startup, stamps, slippage, miss route and parity tests

Eight more test files state the property they pin as a present-tense
fact. Incident narratives (a dated storage stall, a week of zero tuning
events, a two-project poisoned ledger, a twenty-site owner audit) become
the failure shape each test defends; one-install figures that name a rule
become a general worked example with the calibration numbers kept. The
family-grouping regression guard is renamed for what it checks.

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

tests/test_session_slippage_readout.py

@@ -1,4 +1,4 @@
-"""Which rules fired this session, which changed an action, which did not (#4216).
+"""Which rules fired this session, which changed an action, which did not.
 
 WHY THIS CANNOT BE ASKED OF THE SERVER
 
@@ -7,13 +7,13 @@ a SESSION-scoped answer has to be assembled where a session is a thing that
 exists. That is the plugin, from four ledgers four hooks already write:
 
     .rules.ids      an arm NAMED the rule           (a teaser was shown)
-    .opened.ids     the session called get_rule     (#4100)
-    .acted.ids      the session called rule_outcome (#4216, new here)
-    .checkpoint.ids the rule HELD an act            (#4214)
+    .opened.ids     the session called get_rule
+    .acted.ids      the session called rule_outcome
+    .checkpoint.ids the rule HELD an act
 
-EVERY LINE IS AN OBSERVED TOOL CALL. Nothing asks the model what it followed;
-milestone 386 ruled that out because a model asked "did you apply rule 156?"
-will say yes. These record what happened.
+EVERY LINE IS AN OBSERVED TOOL CALL. Nothing asks the model what it followed,
+because a model asked "did you apply rule 156?" will say yes. These record
+what happened.
 
 WHY THE COMPACTION SEAM
 
@@ -21,8 +21,8 @@ A rule read and left unresolved is invisible by construction — it looks
 exactly like a rule that worked. The compaction is where that invisibility
 becomes permanent: the turns holding the evidence are summarised away, and an
 unjudged thing that survives as nothing is how a decision quietly becomes
-nobody's. A PreCompact hook's stdout becomes the summariser's instructions
-(#3680), so this does not say "you slipped" — it says which ids must be
+nobody's. A PreCompact hook's stdout becomes the summariser's instructions,
+so this does not say "you slipped" — it says which ids must be
 carried through, which is the one thing a summary can do about it.
 
 WHAT IS PINNED: the arithmetic, and which conditions produce which lines. NOT
@@ -63,8 +63,7 @@ def ledgers(tmp_path, *, named=(), opened=(), acted=(), held=()) -> Path:
 
     Not hand-rolled files: `scribe_rules_append` is what creates the evidence
     twin these read from, so a fixture that wrote the bytes itself would keep
-    passing if the twin stopped being written — which is the whole defect
-    #4217 found.
+    passing if the twin stopped being written.
     """
     d = tmp_path / "scribe-priorart"
     d.mkdir(parents=True, exist_ok=True)
@@ -140,7 +139,7 @@ def test_a_rule_read_with_no_outcome_is_the_headline(tmp_path):
 
 def test_a_rule_that_held_an_act_is_reported_separately(tmp_path):
     """The strongest evidence a rule changed something: it stopped a call
-    before it ran (#4214). Kept apart from `read` because reading a rule and
+    before it ran. Kept apart from `read` because reading a rule and
     having it alter what you did are different claims."""
     out = readout(ledgers(tmp_path, named=[156], opened=[156], held=[156]))
     assert "held an act" in out and "156" in out
@@ -158,7 +157,7 @@ def test_a_session_that_resolved_everything_makes_no_accusation(tmp_path):
 
 
 def test_a_session_no_rule_touched_says_nothing_at_all(tmp_path):
-    """Rule 115's reasoning: a fresh install must not be told something is
+    """A fresh install must not be told something is
     wrong when the truth is that nothing has happened yet."""
     d = tmp_path / "scribe-priorart"
     d.mkdir(parents=True)
@@ -256,14 +255,12 @@ def test_the_recorder_is_shell_valid():
     subprocess.run(["bash", "-n", str(RECORDER)], check=True)
 
 
-# ── Evidence outlives the compaction; exclusions do not (#4217) ────────────
+# ── Evidence outlives the compaction; exclusions do not ───────────────────
 #
-# THE DEFECT THIS PINS, measured before it was fixed: across six sessions on
-# the instance this was built on, 208 `get_rule` calls produced 3 surviving
-# ledger entries. `.opened.ids` was doing two jobs with opposite lifetimes —
-# "this context holds the rule" (must be forgotten at a compaction, and three
-# hooks depend on that) and "this was opened" (which no compaction makes
-# untrue). The sweep, correct for the first, was deleting the second.
+# Two jobs with opposite lifetimes: "this context holds the rule" (must be
+# forgotten at a compaction, and three hooks depend on that) and "this was
+# opened" (which no compaction makes untrue). One ledger doing both loses
+# nearly every opened rule to the sweep, which is correct only for the first.
 
 def test_the_readout_is_unchanged_by_the_sweep(tmp_path):
     """The readout runs AT the compaction. If the sweep took its inputs it