docs(adr): land ADR 0158 — the silent-controls taxonomy the ledger already pointed at (#145)

* feat(coord): announce yourself to the other sessions in this repo

Every coordination control in this repo is PULL-based: a new session discovers
its peers from the SessionStart banner and the peers learn nothing until someone
trips the collision gate. That is too late for the collision that costs the most
-- two sessions building the same THING in different files, where nothing
file-shaped can catch it. This closes the push direction.

It ASKS, it cannot send. Hooks are shell commands and session messaging is MCP,
so the hook prints the instruction, the live peer roster and the id-resolution
rule at the first prompt that has intent to report; the model does the sending.

UserPromptSubmit, not SessionStart: at SessionStart a session knows it exists and
nothing else, so it can only say hello -- the interrupt without the information.

THE ID RULE IS THE PAYLOAD, and it is counter-intuitive enough that the text
states it with its evidence. The registry id in this repo's banners is NOT the
MCP session id; measured, a registry id and an MCP id for one session shared no
characters. Branch does not join them either -- the two rosters reported
different branches for the same checkout in 2 of 6 cases. Only cwd joins, and it
must be matched EXACTLY: every worktree cwd is an extension of the primary's, so
a prefix match resolves a peer in the primary to an arbitrary worktree session.
A registry id passed to send_message fails SILENTLY, which reads as the peer
ignoring you.

EVERY DECISION LEAVES A RECEIPT, because the bug being fixed was a hook that was
wired, fired, resolved nothing and exited 0 for weeks -- byte-identical to a
healthy hook with no peers. For the same reason the shim carries its OWN
missing-script notice: every receipt the hook writes lives INSIDE the script,
strictly downstream of the resolution failure that IS the bug, so the shim is the
one surface that still reports when the script does not resolve. It is gated on
presence.ps1 so the entry stays silent in every unrelated repo on the machine.

It always exits 0 -- a UserPromptSubmit hook that fails can block the user's
prompt. It consumes presence.ps1 and therefore the single liveness fence; it does
not invent a second notion of live. A separate 'mefor-announce' marker keeps it
outside install-coordination's mefor-coord strip and outside the website repo's
mefor-web-announce entry in the same settings file, so no installer can delete
another's hook, and -Only UserPromptSubmit -Uninstall removes announce alone
without disarming the collision gate.

* test(coord): pin the announce hook, and the anti-no-op wiring class

Most tests for a hook like this assert an ABSENCE, and a hook that does nothing
at all satisfies every one of them -- which is precisely the production failure
being fixed. So the silence assertions are paired with a positive arm: two tests
run the SAME runner against fixtures differing only in whether a peer exists, and
if the silence tests ever start passing for the wrong reason the positive one goes
red first.

test_announce_wiring.py is the class the repo had no test for AT ALL: does the
thing that gets INSTALLED reach a script that EXISTS, and does it say so when it
does not? Its absence is exactly how a wired-but-inert shim survived for weeks.
test_every_wired_script_exists_in_this_checkout was written FIRST and watched
fail, naming the missing script and printing all three paths it scanned; a green
gate is only evidence if it was shown it can see the failure.

Also pinned, each because it was got wrong somewhere first:

- The foreign UserPromptSubmit entries -- another repo's shim and an unmarked
  waiting-flag cleanup -- survive install AND uninstall byte-identical. That is
  the only thing standing between a one-line wiring edit and deleting a hook this
  repo does not own.
- A peer with no StartedAt ranks LAST, not first. ConvertFrom-Json coerces
  ISO-8601 to DateTime while the '' fallback stays String; Sort-Object over that
  mixed column raises ZERO errors and puts the empty string FIRST, so without an
  explicit projected key the least-trustworthy row silently takes the top of a
  capped target list.
- NO_SESSION_ID and DISABLED write their receipt with NO injected -StateDir. An
  earlier draft resolved the state dir after those branches, so the receipt was
  unwritable in production while a test that always injected one went green.
- Self is excluded by BOTH nets independently: a roster that cannot tell you from
  a sibling makes the session message itself.
- Hostile peer text cannot escape the peer-data block or emit a non-ASCII byte,
  a hostile session id cannot escape the state dir, and two ids that sanitise
  identically get two markers.
- Two concurrent runs announce exactly once. session-context.ps1 is registered
  twice on this box today, so double firing is a live pattern, not a hypothetical.

* docs(coord): document announcing yourself, and correct a false claim about .claude

WORKTREES.md gains the "Announcing yourself" section that the hook's own emitted
text and the shim's missing-script notice both cite by name, so the pointer has to
land on main in the same merge. It states the id rule ONCE, as the source of
record: registry id is not the MCP id, cwd is the only join key and must be
matched exactly rather than by prefix, a usable id starts with local_, and a wrong
one fails silently.

It also states what the change does NOT do. There is no receive-side hook, so the
rule that an announcement is peer DATA -- not an operator instruction, and not
something to reply to -- lives in the prose and in the fixed message shape and
nowhere else. Reachability is given honestly: presence.ps1 is authoritative for
who EXISTS, list_sessions only for who can be MESSAGED, and measured, they
disagreed 6-to-1. Cost is stated rather than left to be discovered.

CORRECTION, and it is why this doc change is in scope rather than deferred: the
same chapter claimed ".claude/settings.json is tracked (shared across worktrees)".
It is not. /.claude/ is git-ignored, and git ls-files .claude/ returns nothing --
so a worktree's copy is a creation-time snapshot nothing refreshes and several
siblings have none at all. That sentence sat at the exact point a reader decides
where to install a hook, and it argues for the wrong answer; the new section
directly contradicted it.

SESSION-DRIFT-CONTROLS.md records announce as the only PUSH control in the D4
layer, plus the two new guarantees worth tracking separately: that wiring reaches
a script that exists, and that a resolution failure is now reported by the shim.

* fix(coord): stop the collision gate blocking files a peer committed and finished

Reported by another session with a repro: it committed a file, went clean, said
in writing it was done and handed the file over -- and the peer it handed off to
was still refused the edit.

overlap.ps1's `Files` is the UNION of what a branch COMMITTED-and-not-yet-landed
with what is dirty in its tree. The gate denied on any live row in that set, so
"this branch authored it" was treated as "someone is typing in it right now".
Those are different claims. The first stays true for the branch's whole life;
only the second is what the gate exists to detect.

It self-clears on merge -- overlap already intersects three-dot with two-dot so a
LANDED branch stops claiming its files. But nothing clears it before landing, and
with PRs currently unable to merge, "until it lands" is indefinite: the blocked
set grows monotonically and is never released. Two sessions that coordinated
correctly and explicitly still cannot hand a file over. That is precisely the
failure this gate's own docstring names -- a gate that cries wolf gets
uninstalled.

overlap.ps1 already told callers to treat its signals differently ("block on
live, mention dormant"), but no caller COULD: the row unioned the two signals
away. So the row now carries `Dirty`, and the single-file query sets
`MatchedDirty` saying which signal actually matched.

The gate now DENIES only on an uncommitted edit in a live worktree, and REPORTS
committed-and-clean as context instead -- the peer may already have done what you
are about to do, which is worth knowing and not worth refusing over.

Fails SAFE across the upgrade: a cached row predating `MatchedDirty` has no such
property and is treated as dirty, so the gate degrades to its previous
over-blocking rather than silently permitting a real collision.

Also, while in the file: `git status` now runs with --no-optional-locks. A plain
status REWRITES the index of the repo it inspects, and this walks every peer
worktree -- so merely asking "what is in flight" was mutating other sessions'
checkouts.

Verified against the live repro and both directions: the reported file now
allows with context; a file with uncommitted changes in a live worktree still
denies; an untouched file stays silent.

* feat(coord): lead the announce roster with the claim note, not the worktree name

Reported by the session it happened to: its worktree is named
inter-session-communication-*, auto-generated at creation from a task that
session has never worked on -- it has been doing ASVS scorecard work for its
entire life. The directory name is the most visible identifier in presence.ps1,
overlap.ps1 and this hook's output, and it had already misled TWO sessions
(including this one) into guessing that session was building the announce hook.

A worktree name is a creation-time label, not a statement of current work, and
nothing keeps the two in sync. The claim note is the only field written
DELIBERATELY to say what a session is doing, so the roster now prints it, and the
legend tells the reader to prefer it over the name.

Joined on the claim's `worktree` path, normalised the same way as every other cwd
key here. Fail-open throughout: no claims directory, an unreadable claim, or a
peer with no claim all just mean the name is the only thing we have -- which is
exactly the status quo, never an error.

Same session also flagged that the branch I read for it from list_sessions was
stale (a spent, merged branch). The announce text already refuses to join on
branch and says why; this is a second, independent reason not to trust it.

* docs(coord): name the silent-control defect class in the drift inventory

A control that cannot distinguish 'ran and resolved' from 'ran and found nothing'
is not installed, however it looks. The announce shim outlived every other
silent-control defect found the same day BECAUSE it printed a status message --
which is more convincing than silence.

The structural cause is the reusable part: every receipt that hook would have
written lived inside the script the shim failed to find, so every check sat
strictly downstream of the failure it existed to detect. Looking was not
neglected, it was impossible. The question to ask of a new control is which
surface still reports when the control itself fails to load.

Formulation owed to a peer session that hit four instances of this class in one
day and named it more sharply than I had.

* docs(coord): record the broadcast constraints six sessions learned the hard way

Announce-on-join introduces a session; it does not let an established one push an
operational notice. That increment is deferred, and on 2026-08-01 six sessions
rehearsed it by hand for four hours. Three constraints fell out, recorded so the
next attempt does not rediscover them:

- A broadcast needs an EXPIRY or a predicate the RECIPIENT can evaluate, never a
  promise from the sender. A merge freeze shipped with 'lift when #119 merges';
  #119 died on an unrelated CI timeout, so five sessions held on a condition that
  could not arrive and a second round was needed to retract it.
- 'Don't do X' is the wrong primitive when automation already has X armed. The
  freeze asked for restraint while six PRs had auto-merge ARMED and would have
  landed with nobody clicking anything. The right ask was an action: disarm.
- Coordination a tool cannot read does not count. Two sessions agreed IN WRITING
  to hand over a file and the gate still refused, because the agreement was prose
  and the gate reads git.

Field data from the sessions that lived it, not speculation.

* test(coord): pin overlap's dirty-vs-committed signals against real git

Nothing drove overlap.ps1's row computation against a real repository, so the
question "does MatchedDirty hold when a file is dirty AND committed at once" was
unanswerable by the suite. Raised by the session that spent an evening in exactly
that state.

THAT CASE IS THE ONE THAT FAILS SILENT, which is why it gets a real fixture
rather than a stub row. A peer with uncommitted edits in one region and landed
work in another is a genuine collision. Had MatchedDirty been derived from the
committed diff instead of the working tree it would read FALSE there, the gate
would allow, and two sessions would write one file with nothing reported. The
over-block this replaced was loud and annoying; that would be quiet and cost
someone their work.

Verified the tests can SEE it rather than assuming: sabotaged the row to publish
an empty Dirty set -- the precise mis-implementation warned about -- and both
MatchedDirty assertions went red; restored, all five green. A test written after
the code, never observed failing, is a test of nothing.

Also pins that overlap does not rewrite a peer worktree's git index, by comparing
the index mtime across two queries. An observer must not perturb what it
observes, and this one was doing so on every PreToolUse before f55d6c6.

Stub rows would only have asserted that the plumbing carries a value someone else
computed; the whole question here is what git actually reports.

* test(coord): assert a wired coordination hook resolves to a script that exists

Raised by the session that traced the shim: the coordination hooks are not
installed copies, they are inline commands that locate their script in a working
tree at every invocation. If neither base yields the file, Test-Path fails, the
loop ends, nothing runs, and the tool call proceeds with no hook and no signal.
"The hook is uninstalled" and "the hook ran and permitted this" are
indistinguishable from outside, and nothing was watching.

Not hypothetical: a foreign UserPromptSubmit entry sat in this same settings file
for weeks probing a script that exists only in another repo.

The risk composes badly for collision_gate.ps1 specifically, which now (a) fails
OPEN on any error, (b) denies less by design after the dirty-vs-committed split,
and (c) silently no-ops when unresolvable. Individually defensible; together the
realistic bad day is "the gate was never running and nobody noticed". This closes
(c) -- the observation is not mine, and it is a good one.

Found immediately on writing it: FIVE user settings files across account
directories, not the one I knew about. The informational test also prints the
original defect as output rather than leaving it invisible:
  FOREIGN UserPromptSubmit [mefor-web-announce] -> scripts/hooks/announce.ps1:
  RESOLVES NOTHING HERE
It is another repo's entry, so this reports it and does not touch it.

Carries a NEGATIVE CONTROL, because the assertion passed on the first run and a
green that has never been shown to fail is not evidence. The real hooks cannot be
unwired to prove the predicate works -- the primary checkout is shared with live
sessions -- so it is exercised against a path known not to exist.

Local-machine only: CI has no user settings and these skip there, which means CI
does NOT guard this property. Said plainly, and every test prints what it scanned
BEFORE it can skip, per test_gate_installed_parity.py -- the pytest config has no
-rs, so a skip would otherwise render as a bare dot with no reason.

* docs(adr): ADR 0158 silent controls, plus a session handoff

Session ended on an owner stop-work instruction at 96% weekly account usage, so
this lands the two things that would otherwise have existed only in a transcript.

ADR 0158 records a defect class that recurred at least a dozen times across
independent surfaces in one working day, in at least two sub-classes: a bound
stated independently of the thing it bounds, and a control that cannot observe or
act on its own failure. Its spine is that a signal carrying too little
information to act on makes every reader re-derive significance by hand until one
of them derives it wrong -- so a correct-but-useless RED costs what a silent green
costs.

EVERY FIGURE IN IT WAS RE-DERIVED BY SOMEONE WHO DID NOT PRODUCE IT, against the
repository and the GitHub API. That pass refuted six claims, including four CI
numbers that were already merged, and including corrections this session had
itself issued hours earlier. Seven retractions are recorded INSIDE the document,
each carrying a found-by tag -- because the central empirical finding is that no
retraction was made by the author of the claim it retracts, and that is invisible
if attribution is smoothed into one voice.

Shape over detection is reported as a ratio rather than flattered: three fixes are
covered by tests in required CI legs, two by tests that always skip in CI, one by
a workflow change with a live residual, and the rest are corrected prose or still
open. The Decision separates ENFORCED rules, each naming its gate, from CONVENTION
that is knowingly re-breakable.

The handoff records what is pushed, what is filed-not-built, and the traps -- a
linked worktree's .git being a FILE, a Windows Python unable to read MSYS paths, a
raw hasher giving a false mismatch against a git blob on CRLF, and claim.ps1
silently discarding a note refresh. Each is stated as a fact plus its measurement.

It also records, first, the five claims this session got wrong -- including
retracting a CORRECT estimate on the strength of an incorrect measurement, and
sending that false claim to four sessions and the correction to only three.

One more arrived while committing this: the leak gate rejected the handoff for a
branch slug, on a line a standalone run of the same scanner had passed. The hook
scans STAGED files; the standalone run scanned tracked ones. Two scopes, one tool,
and only the fail-closed gate could see it. Recorded in the handoff.

No engine behaviour changes.

* docs(adr): land ADR 0158 -- silent controls, green signals that mean nothing

ADR 0158 was authored and committed in 994bfb1 on
claude/intersession-communication-hooks-a52335, a trailing commit pushed about an
hour and a half AFTER that branch's PR (#133) had already squash-merged. It
therefore never reached main and no PR carried it, while the coordination ledger
had already allocated the number: docs/adr/README.md stopped at 0156 and 0158 was
taken, so the index pointed at a document that did not exist.

That gap had a cost. At least four sessions cited this silent-controls taxonomy as
"ADR 0157" -- an unrelated HA demotion-safety document allocated to another
worktree and still in flight on PR #139. The document that settles the citation
was the one sitting unmerged.

This branch is cut from 994bfb1 itself, so the original commit stays in history
and authorship is exact. The prose, voice and ASCII-only convention are its
author's. This commit drops the session handoff and makes three factual
corrections where main moved underneath the branch after it was written, each
tagged inline in the ADR's own update convention rather than silently rewritten:

  * 0fdc326 is unreachable from main (this repo squash-merges). It is now given
    as "merged as 851c849 (#130)", matching the mapping the ADR already uses for
    7ebb2ff/2a6649fb.
  * transports/email.py and transports/direct.py were cited as carrying the same
    bare starttls() call. 093db33 (#132) gave both an explicit verifying context;
    pipeline/alert_sinks.py:384 is now the only remaining instance.
  * The "the false sentence is still there" claim (five sites, one of them
    numbered Decision rule 13) is closed out: on main the clause survives only
    inside its own CORRECTED block at :5270 and as a quotation at :7476. The
    interval is recorded; the rule it produced is unchanged.

HANDOFF-announce-hook.md from 994bfb1 is deliberately not landed: it is session
state rather than project documentation, no root HANDOFF-*.md has ever existed on
main, and it would publish local shim mechanics into a public repo. It stays on
its own branch.

Verified: exactly one commit in the repository ever added a 0158 ADR and exactly
one 0158 filename exists across all refs, so nothing competes for the number. The
index row is unchanged from 994bfb1 and appears exactly once.

No engine behaviour changes.

* docs(adr): make the 0158 TLS update non-perishable

The correction I added said 093db33 (#132) left alert_sinks.py as "the only
remaining instance on main". That is a checklist-shaped claim with an expiry
date: BACKLOG #323 layer 3 (PR #142) closes the alerts call site, and the
sentence goes false the moment it lands. Dating the observation does not help a
reader who greps for it in a month and finds nothing.

Restated as what happened rather than what is currently true -- #132 closed the
two connectors, the alerts call site is tracked as #323 layer 3 -- so it holds
whether or not #142 merges, and it says outright that the current state must be
grepped rather than cited from here.

Deliberately does NOT assert that #142 closed the cell: #142 is open at time of
writing, and asserting a merge that has not happened is the same defect pointing
the other way.

found by: the repo-security-review session, which owns #142 and re-derived all
three call sites against origin/main before raising it.

* docs(adr-0158): replace rotting line-number citations with greppable strings

The document's own rule, applied to itself: a quoted string survives a file
edit, a line number does not. Ten citations replaced.

WHY NOW. All three ci.yml citations (:229, :233, :254) resolve to unrelated
text the moment #138 lands, and six docs/BACKLOG.md citations had ALREADY
rotted on main before that -- +14 to +40 lines of drift from #345/#346/#347
being appended, with every cited claim surviving verbatim at a new address.
Measured fresh against origin/main and against #138's branch, not reused from
the report that found them.

TENSE, not just addresses. Two of the quoted strings do not survive #138 --
"Measured over the 11 PASSING windows-2025 runs" and "1.46x" are both deleted
by it, because #138 ADOPTS this ADR's retractions 1-3 wholesale (12:31, 21:34,
25:51, 1.006x, 1.206x, pools 42/39/36). Left in the present tense those two
sentences would ship knowingly false the hour #138 merges, so they now say
what ci.yml stated when this was written. The retractions themselves are
unchanged and are vindicated by #138, not contradicted.

ANCHORS ARE SINGLE-LINE ON PURPOSE. A first pass rewrapped two quotes across a
newline, which makes them ungreppable and would have swapped one rot for
another. Every anchor is now verified to grep as one line AND to resolve in
the tree it points at -- "ZERO tests failing" resolves in ci.yml both on main
and after #138.

pyproject.toml:266 was simply wrong: the zizmor pin is at :271, in the group
opening at :268. Replaced with the group name, which is what the sentence
needed and cannot rot. The residual it reports -- that the pin's home is
outside zizmor's paths filter -- is verified TRUE and unchanged.

OUT OF SCOPE, deliberately: line numbers into less volatile files remain
(test_stage_dispatcher.py, claim.ps1, zizmor.yml, install-coordination.ps1,
freethread-smoke.yml, collision_gate.ps1). So the ADR does not yet "state no
line numbers" outright -- see the handoff note.

Author: wshallwshall