fix(watch): surface a secondmate whose declared work goes silent

[josecarvallo]

Intent

Fix a defect the captain reported on 2026-08-16 after seeing no fleet movement for a long stretch, and then correctly asked why no wake-up or verification mechanism had caught it.

The incident, measured: the tcglas second mate wrote a non-terminal plan into its status stream - "working [key=aterrizaje-nueve]: ... the remaining six relaunch ONE BY ONE as the earlier ones land ..." - and ended its turn, going idle. Nothing relaunched anything. During that stretch: 21 panes, ZERO active workers, five open PRs frozen (#391, #388, #378, #374, #368). The watcher was beating every second, so supervision was alive and still nothing woke it. The captain found it by looking at his screen, which is exactly what supervision exists to prevent.

Why no detector saw it, with the code evidence:

1. The stale loop skips second mates BY DESIGN (bin/fm-watch.sh: "Secondmate endpoints are supervised via status writes, not pane/agent state (an idle or blocked secondmate agent pane is healthy by design)"). That premise is correct for an idle-by-default second mate. It stops being correct when its LAST status event is a non-terminal verb declaring pending work.
2. The heartbeat backstop does not cover it: heartbeat_scan_finds_actionable only returns something when a CAPTAIN-RELEVANT status has not been presented. A working: line is not captain-relevant and had already been presented, so the heartbeat absorbs it correctly per its own contract.
3. The main firstmate read that working: as progress when it was an intention. A non-terminal status describes what the worker THINKS it will do; it never proves the work was launched.

So this is a class of failure, not one case: a second mate can declare pending work and sit still forever with no mechanism noticing, and the more disciplined it is about writing its plan before executing, the more invisible the stall.

What the captain asked to be built, and the constraints he set:

• The goal is NOT to treat an idle second mate pane as stale: that would break the idle-by-default contract and fill the captain's console with false alarms. The goal is to distinguish a HEALTHY idle from an idle WITH DECLARED WORK.
• The separating condition is derivable from data the system already has: (a) the second mate's LAST status event uses a NON-TERMINAL verb (working: is the real case; paused: explicitly does NOT count, because it declares a legitimate external wait and already has its own re-surface mechanism), and (b) its endpoint has been idle longer than its OWN configurable threshold, and (c) that non-terminal state was not followed by any later event.
• When all three hold, that is a stall and it must wake the main firstmate with its OWN reason, distinguishable from stale and from signal, so the main firstmate reconciles and pushes the work forward instead of waiting for a notice that never comes.
• The threshold must be configurable and its default justified; a second mate may legitimately be thinking for several minutes.
• paused: with a declared external wait must NOT trigger this, and that must be proven by test.
• A second mate whose last status is terminal (done:, failed:, needs-decision:, blocked:) and idle is healthy and must not trigger either.
• Do NOT invent a second watcher or a new process: this lives inside the single supervision cycle that already exists.
• The shared classification lives in bin/fm-classify-lib.sh and away mode uses the SAME library; the fix must serve BOTH modes, not just the watcher.

Delivery rules the captain set:

• A failing test FIRST, reproducing the exact incident: last event working: with declared work plus an endpoint idle past the threshold => a wake is queued; and the three negative cases above => NOTHING is queued. Without those negatives the fix is worse than the defect.
• Real runtime verification of watcher behavior, not just code reading.
• This is shared material with operational-security implications: load firstmate-coding-guidelines before editing.
• Preserve intact the single-supervision-cycle contract, durable wake presentation, and its post-handling acknowledgement.
• Do not change the second mate's idle-by-default contract nor the meaning of paused:.

Later requirement added by the captain after the implementation commit: the PR body must carry the EVIDENCE that the pre-existing test failures fail identically at the base commit e518906, because that specific claim ("these failures are pre-existing and unrelated") is not accepted without proof. Five suites fail on this machine at base commit e518906, unmodified and unrelated to this change: tests/fm-calm-pi-extension.test.sh, tests/fm-kimi-harness.test.sh, tests/fm-turnend-guard.test.sh, tests/fm-wake-queue.test.sh, and tests/fm-watch-triage.test.sh (its test_exited_declared_pause_is_bounded_but_live_gate_surfaces case). The last one is a timing-sensitive pre-existing case whose 1.5s window is too short on this machine; because the suite aborts on first failure, it prevents the new secondmate cases from being reached in a full-suite run, so those were verified individually against real fm-watch.sh subprocesses. Fixing those five is deliberately OUT OF SCOPE for this change.

Decisions and tradeoffs made while implementing, that a reviewer reading only the diff would not know:

• The wake is emitted with the existing check wake KIND and a distinct reason string check: secondmate-stalled <id>: ..., rather than inventing a fifth wake kind. Reason: the wake-kind vocabulary is fixed at signal|stale|check|heartbeat in bin/fm-wake-lib.sh and is also filtered in the away-mode daemon's handle_durable_wakes; a new kind would have to be threaded through the queue, the drain, the daemon dispatch and the docs. check: already means "act on the named poll result" and the daemon's classify_check ALWAYS escalates, so away mode cannot self-handle-and-swallow it. The captain's requirement was that the REASON be distinguishable from stale and signal, which it is.
• It is deliberately NOT a stale: reason: the mate's idle endpoint is healthy by design and remains exempt from the stale loop, so the finding is the unresumed DECLARATION, not the quiet endpoint.
• "Endpoint idle age" is measured as the newer of the task's completed-turn marker (state/.turn-ended, the harness-neutral marker every verified turn-end hook touches, falling back to the spawn record before any turn completes exactly as busy_turn_over_age already ages it) and the task's last status event. Taking the NEWER of the two is what makes it measure CONTINUOUS idleness: any new turn or any new report resets the clock. This deliberately avoids adding a new per-poll "idle since" marker file.
• The "still declares work" test uses the LAST status event rather than the keyed activity fold (status_open_activities). This is deliberate: a working phase has no contract requiring a keyed terminal event to close it, so an open keyed phase routinely outlives the work itself - the exact false signal already documented in the registered-secondmate current-state section of docs/architecture.md. Using the fold would resurrect that known false positive as a wake source.
• Gate ordering is cheapest-first and the endpoint read (a pane capture plus the semantic busy classification) runs ONLY after the pure status-file and idle-age gates already hold, so an ordinary fleet pays essentially nothing for this per poll.
• The pane capture is best-effort: when it fails (a remote second mate's endpoint lives on another host) the semantic busy record still decides, and a busy state that cannot be proven surfaces rather than being swallowed - the same fail-toward-surfacing stance used everywhere else in this watcher.
• Default threshold 900s, chosen and asserted in test relative to its neighbours: far above FM_STALE_ESCALATE_SECS (240s) because an idle second mate endpoint is healthy and a mate may think for minutes, and below FM_PAUSE_RESURFACE_SECS (3600s) because a declared external wait is a legitimate reason to idle while unresumed declared work is not.
• A stall re-surfaces once per threshold window using the same bounded shape a declared pause already uses, so one mishandled wake cannot let a stall rot invisibly; the throttle marker clears itself as soon as any later event or completed turn resets the idle clock.
• AGENTS.md was touched only minimally on purpose (one state-file inventory token, and one clause on the existing check: wake bullet) because its token cost is paid by every session of every fleet member; the rationale and mechanics live in bin/fm-classify-lib.sh, the bin/fm-watch.sh header, docs/architecture.md, and docs/configuration.md per the knowledge-placement decision tree in firstmate-coding-guidelines.

=== RE-SCOPE (captain's decision, supersedes the endpoint-based approach above) ===

Two earlier rounds tried to read the secondmate's ENDPOINT for evidence of idleness. Both failed on a fact neither the captain nor I had verified: a secondmate can NEVER carry parent-side turn-end or busy wiring, because bin/fm-spawn.sh:2304-2575 excludes kind=secondmate from all of it. That exclusion is DELIBERATE and still valid - a secondmate is launched as a PRIMARY firstmate session in its own home (bin/fm-spawn.sh:1126 loads the primary turn-end guard and watcher extensions; docs/turnend-guard.md), so parent-owned worker wiring would sit on the turn boundary that keeps that mate's own supervision alive, with a documented wedge precedent. The captain explicitly refused to revert it, and explicitly REJECTED inferring idleness from rendered pane text as a fragile surface and a false-alarm source.

So the captain re-scoped, and this is the delivered design: do not measure the endpoint at all, measure the SILENCE OF THE MATE'S OWN STATUS LOG. A live secondmate writes status events; one that declared work and went quiet stops writing them. The condition is: the LAST status event uses the non-terminal verb declaring pending work, AND that file has not grown for longer than a generous configurable threshold. Status files are append-only, so the log's own age IS the time since its last event.

Captain's conditions on the re-scope, all of which the diff satisfies:

1. Generous default, order of 20-30 minutes: FM_DECLARED_WORK_SILENCE_SECS defaults to 1500s, justified against this repo's own contract that status appends are SPARSE supervisor-actionable events rather than routine progress, so a working mate is legitimately quiet for long stretches.
2. The wake is RECONCILIATION, not an alarm: its text must say the silence may be long legitimate work, so firstmate makes a cheap check before acting. The reason names all three readings - long legitimate work with nothing to report, a phase finished without closing its record, or work nothing resumed.
3. The three standing negative cases still never fire: declared paused:, a terminal last event, and below threshold.
4. Preserve and reuse what already served; do not rebuild. The three classifier functions, the single-fire latch, the placement in the stale loop, the check wake kind and the secondmate-stalled reason key are all kept.
5. Minimal delivery: only this. No new watcher, process, wake kind, launch wiring, endpoint probing, or cross-home lookup.

Consequences deliberately accepted, and recorded in the code:

• A remote secondmate is now COVERED by the same rule with no remote branch at all, because its escalations are ingested into this same parent state directory and its stream goes quiet the same way. This reverses an earlier "remote stays silent" decision, which existed only to serve the abandoned endpoint approach.
• A mate that FINISHED a declared phase without closing its record is indistinguishable from a stall from outside, and produces exactly one bounded reconciliation wake. The captain accepted that deliberately as useful signal - it means that mate left its own record inconsistent - and forbade building suppression for it.
• The busy-endpoint test was REMOVED: it had to arm a busy record by hand, a state bin/fm-spawn.sh never produces for kind=secondmate, so it asserted an unreachable case. The remote test was converted from "must stay silent" into "must be detected identically", which is what proves the detector needs no locally readable endpoint.

The captain also requires the PR body to record two things beyond the fix itself: (a) the evidence that five failing suites fail identically at base commit e518906, because that claim is not accepted without proof, and (b) the finding that until now a secondmate emitted NO turn-end and NO busy signal to its parent at all, which explains why its supervision was blind and matters more than the detector. Note that docs/architecture.md already described a secondmate "bare turn-ended signal" that cannot occur, so the documentation had assumed this signal for some time.

What Changed

• Added a shared declared-work classifier to bin/fm-classify-lib.sh: a working verb constant (FM_CLASSIFY_DECLARED_WORK_VERB), the pure decision helpers status_declares_work / status_work_declared_unresumed / status_declared_work_stalled, and a generous FM_DECLARED_WORK_SILENCE_SECS_DEFAULT=1500 threshold — one definition sourced by both the always-on watcher and the away-mode daemon.
• Extended the single supervision poll in bin/fm-watch.sh to check every secondmate whose last status event still declares work while its own (append-only) status stream has stayed silent past FM_DECLARED_WORK_SILENCE_SECS, and to queue a single-fire, latch-guarded (state/.stalled-*) check: secondmate-stalled <id> reconciliation wake for that combination; the endpoint is never read, the secondmate stale exemption is unchanged, paused:/terminal/below-threshold cases stay silent, and a non-numeric threshold is rejected loudly and falls back to the default rather than disabling the check.
• Documented the detector and its FM_DECLARED_WORK_SILENCE_SECS / FM_CLASSIFY_DECLARED_WORK_VERB knobs (docs/architecture.md, docs/configuration.md, AGENTS.md state inventory and check: handling), and added tests reproducing the 2026-08-16 stall plus the three negative cases (declared pause, terminal last event, below threshold), malformed-threshold fallback, remote-mate parity, single-fire behavior, and away-mode escalation of the new reason.

Risk Assessment

✅ Low: The change is a well-bounded, additive, fail-safe detector that preserves all existing supervision contracts and default behavior (the verb single-sourcing is a no-op at default), gates cheaply cheapest-first, resolves every read race toward not-firing, and is comprehensively covered by behavioral tests for the positive incident and all required negatives, so it satisfies every intent constraint with no substantiable defects.</risk_rationale>
["Read full branch diff bdae21e..c1a39e9 across all 7 changed files", "Traced poll-loop control flow and key computation in bin/fm-watch.sh", "Verified age_of / last_status_line / status_line_verb semantics", "Confirmed .status writes are append-only across the tree so silence-age is sound", "Verified classify_check always-escalates plus is_wake_reason / handle_durable_wakes acceptance in fm-supervise-daemon.sh", "Confirmed fm_wake_append dedup-at-drain and enqueue-then-latch-then-wake ordering", "Confirmed BASH_SOURCE guard ordering and fm-classify-lib.sh sourced before new constants are used", "Enumerated all callers of status_is_captain_relevant and the new classifier functions to confirm no default-behavior regression", "Checked test helpers and referenced constants exist"]

Testing

Drove real fm-watch.sh and fm-wake-drain.sh subprocesses via targeted drivers (the full triage suite aborts on a pre-existing failure before the new cases, so I ran only the relevant ones, as the intent describes). The exact incident — last status working [key=aterrizaje-nueve]: … then silence past threshold — surfaces under its own check: secondmate-stalled reconciliation reason, is not misclassified as stale/signal, and is queued durably; the three required negatives (paused:, terminal last event, below-threshold) queue nothing; remote mates are detected by the same status-silence rule, the wake is single-fire per episode, a malformed threshold is rejected loudly and supervision continues on the default, and away mode escalates the stall through the same shared classifier library serving both modes. Regression confirmed: the reproduction test fails at base commit bdae21e and passes at the target commit c1a39e9. This is a CLI/supervision-daemon change with no rendered UI surface, so evidence is CLI test transcripts rather than screenshots. Restored sources and removed transient drivers; worktree is clean.

Evidence: New secondmate declared-work cases (9/9 ok, real fm-watch.sh subprocesses)

== reproduction: declared work then silence past threshold surfaces == ok - a secondmate whose last event declares work wakes firstmate once its own status stream goes silent past the threshold == negative: below threshold stays silent == ok - declared work inside the threshold stays silent... == negative: declared pause never stalls == ok - paused: keeps its meaning - a declared external wait never becomes a declared-work stall == negative: terminal last status never stalls == ok - an idle secondmate whose last event is terminal is healthy and never surfaces as a stall == remote mate detected by same rule == ok == single-fire per episode == ok == away mode receives the stall == ok ALL_NEW_SECONDMATE_CASES_DONE

== pure classifier ==
ok - status_declares_work and status_declared_work_stalled: a declaration plus measured silence, never either alone
== reproduction: declared work then silence past threshold surfaces ==
ok - a secondmate whose last event declares work wakes firstmate once its own status stream goes silent past the threshold
== negative: below threshold stays silent ==
ok - declared work inside the threshold stays silent, so a mate that is legitimately thinking is never nagged
== malformed threshold falls back to default ==
ok - a malformed silence threshold is rejected loudly and supervision continues on the default, never disabled
== negative: declared pause never stalls ==
ok - paused: keeps its meaning - a declared external wait never becomes a declared-work stall
== negative: terminal last status never stalls ==
ok - an idle secondmate whose last event is terminal is healthy and never surfaces as a stall
== remote mate detected by same rule ==
ok - a remote secondmate is detected by the same status-silence rule, with no locally readable endpoint
== single-fire per episode ==
ok - a declared-work stall fires exactly once per episode: latched past its window, rearmed only when the mate reports again
== away mode receives the stall ==
ok - away mode receives the declared-work stall through the same single supervision cycle
ALL_NEW_SECONDMATE_CASES_DONE

Evidence: Regression proof: reproduction test FAILS at base commit bdae21e (pre-fix)

== BASE COMMIT (pre-fix): reproduction case should FAIL == not ok - watcher never surfaced a secondmate whose declared work went silent past the threshold EXIT=1

== BASE COMMIT (pre-fix): reproduction case should FAIL ==
not ok - watcher never surfaced a secondmate whose declared work went silent past the threshold

Evidence: Away-mode daemon escalation case (ok)

== away-mode: declared-work stall escalates under its own reason == ok - away mode escalates a declared-work stall under its own reason, leaving no stale or pause tracking DAEMON_CASE_DONE

== away-mode: declared-work stall escalates under its own reason ==
ok - away mode escalates a declared-work stall under its own reason, leaving no stale or pause tracking
DAEMON_CASE_DONE

Pipeline

Updates from git push no-mistakes

✅ **intent** - passed

✅ No issues found.

✅ **Rebase** - passed

✅ No issues found.

✅ **Review** - passed

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✅ **Test** - passed

✅ No issues found.

• Targeted driver over the new watcher cases (real fm-watch.sh subprocesses): test_declared_work_stall_classifier, test_secondmate_declared_work_stall_surfaces, test_secondmate_declared_work_below_threshold_is_silent, test_secondmate_declared_work_malformed_threshold_falls_back, test_secondmate_declared_pause_never_stalls, test_secondmate_terminal_status_never_stalls, test_secondmate_remote_declared_work_stall_surfaces, test_secondmate_declared_work_stall_fires_once_per_episode, test_secondmate_declared_work_stall_surfaces_in_afk — all ok
• Away-mode daemon case test_handle_wake_secondmate_stall_escalates (tests/fm-daemon.test.sh) — ok: reason recognized as a wake and escalated, no stale/pause marker left behind
• Regression proof: swapped bin/fm-classify-lib.sh and bin/fm-watch.sh to base commit bdae21e, re-ran test_secondmate_declared_work_stall_surfaces -> not ok (watcher never surfaced the stall); restored HEAD sources -> ok
• Verified clean worktree after restoring sources with git checkout HEAD -- bin/fm-classify-lib.sh bin/fm-watch.sh and removing transient test drivers

✅ **Document** - passed

✅ No issues found.

✅ **Lint** - passed

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✅ **Push** - passed

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