Sub-iii: Remove tmux-inject + Shape A heartbeat-mailbox path; wire SwarmHeartbeatService to emitHeartbeatPulse

Context

Sub-iii of Epic #11993 (Wake substrate evolution: 3-signal model + Shape B heartbeat pulse). Graduated from Discussion #11992 (cycle-3 RESOLVED). See Epic body for full architectural context and Signal Ledger.

Origin Session ID: 8f1a91ee-3ee4-4e4b-9865-b5810f6be353

The Problem

After Sub-i lands WakeSubscriptionService.emitHeartbeatPulse (#11994) and Sub-ii lands the 3-signal derivation + backoff + readiness parser (#11995), two legacy wake-delivery paths remain in the codebase:

1. SwarmHeartbeatService.tmuxInjectPulsePrompt() (line 657) — tmux send-keys-based pulse injection. Dead path for non-tmux harnesses (Codex Desktop is native macOS, no tmux). Pre-bridge-daemon-era leftover.
2. idleOutNudge.mjs — currently calls MailboxService.addMessage to wake recipients (Shape A path). Per @neo-gpt cycle-2 V-B-A: this creates durable MESSAGE nodes (MailboxService.mjs:337,548) + transcript-injected wake-blocks (bridge-daemon:522-538). Unacceptable Codex Desktop mailbox UX (~96 durable msgs/day/identity).

Per Discussion #11992 cycle-3 @tobiu pushback: Shape A is NOT preserved as "diagnostic fallback." Preserving Shape A is the same preserve-the-workaround instinct that motivated rejected #11872 / #11982. If Shape B is substrate-correct, Shape A is just legacy that gets removed.

The Fix

1. Delete SwarmHeartbeatService.tmuxInjectPulsePrompt() method entirely from ai/daemons/orchestrator/services/SwarmHeartbeatService.mjs. No "preserved as adapter" hedge — bridge-daemon already has a tmux adapter (per resumeHarness.mjs:213) if any operator ever genuinely needs tmux delivery; the SwarmHeartbeatService-side tmux-inject is redundant duplicate-of-logic.
2. Replace SwarmHeartbeatService.pulse() Step 7 with per-target emitHeartbeatPulse iteration driven by Sub-ii's 3-signal-decision function: for (target of pulseIdentities) if (active && idle && ready) emitHeartbeatPulse({targetIdentity: target}).
3. Refactor ai/scripts/lifecycle/idleOutNudge.mjs to call WakeSubscriptionService.emitHeartbeatPulse({targetIdentity}) instead of MailboxService.addMessage({to: targetIdentity, ...}). The function's external API stays the same; only the internal mechanism changes. No MESSAGE nodes created.
4. Update wake-substrate runbook (learn/agentos/wake-substrate/PersistentProcessManagement.md + NightShiftLeasedDriver.md) to document the 3-signal model + Shape B canonical wake-pulse path. Remove tmux-injection references; remove Shape A heartbeat-via-mailbox documentation.

Architectural Reality

• Depends on Sub-i (#11994) for emitHeartbeatPulse to exist.
• Depends on Sub-ii (#11995) for the 3-signal-decision function consumed by SwarmHeartbeatService.pulse() Step 7 replacement.
• Bridge-daemon adapter set (osascript / codex-app-server / antigravity-cli / claude-cli / tmux) remains intact in ai/daemons/bridge/daemon.mjs — only the SwarmHeartbeatService-side tmux-inject is removed.
• idleOutNudge.mjs's callers (currently the SwarmHeartbeatService and any direct CLI invokers) see no API change — internal mechanism swap only.

Contract Ledger

Acceptance Criteria

• AC1 — SwarmHeartbeatService.tmuxInjectPulsePrompt() method deleted entirely from ai/daemons/orchestrator/services/SwarmHeartbeatService.mjs
• AC2 — SwarmHeartbeatService.pulse() Step 7 replaced with emitHeartbeatPulse per-target iteration; gated by Sub-ii's 3-signal-decision function
• AC3 — idleOutNudge.mjs refactored to call WakeSubscriptionService.emitHeartbeatPulse instead of MailboxService.addMessage
• AC4 — Unit test verifies idleOutNudge no longer creates MESSAGE nodes (assert post-call mailbox count unchanged)
• AC5 — Wake substrate runbook updated: learn/agentos/wake-substrate/PersistentProcessManagement.md + NightShiftLeasedDriver.md
• AC6 — Post-merge greps: grep -rn "tmuxInjectPulsePrompt|tmux.*pulse" ai/ test/ returns zero; idleOutNudge.mjs does not reference MailboxService.addMessage
• AC7 — Cross-family review per pull-request §6.1
• AC8 — Post-merge operator confirmation: heartbeat pulse causes Codex Desktop to wake when active AND idle AND ready for @neo-gpt (the original symptom #11872 was reframed-and-rejected for)

Out of Scope

• WakeSubscriptionService.emitHeartbeatPulse mechanism — Sub-i of Epic #11993 (#11994)
• 3-signal derivation logic — Sub-ii of Epic #11993 (#11995)
• Bridge-daemon adapter behavior changes — Sub-i / out of scope here
• Bridge-daemon Codex adapter debugging (OQ6) — sibling concern, separate ticket post-client-trial trace

Avoided Traps

• ❌ Preserving SwarmHeartbeatService.tmuxInjectPulsePrompt as "tmux adapter" — bridge-daemon already has tmux adapter; SwarmHeartbeatService-side duplicate is the legacy leftover being removed
• ❌ Keeping Shape A in idleOutNudge.mjs as "diagnostic fallback" — explicitly rejected by @tobiu cycle-3 Discussion #11992 pushback
• ❌ Stub the methods rather than delete — sets a bad precedent for future maintainers (zombie methods); delete entirely
• ❌ Leave PersistentProcessManagement.md outdated — doc drift compounds; the Epic AC7 + AC6 demand runbook update

Related

• Parent Epic: #11993
• Graduation Discussion: #11992
• Sub-i (provides emitHeartbeatPulse consumed by this sub): #11994
• Sub-ii (provides 3-signal-decision function consumed by this sub): #11995
• Files touched: ai/daemons/orchestrator/services/SwarmHeartbeatService.mjs, ai/scripts/lifecycle/idleOutNudge.mjs, learn/agentos/wake-substrate/PersistentProcessManagement.md, learn/agentos/wake-substrate/NightShiftLeasedDriver.md

Handoff Retrieval Hints

• Semantic: query_raw_memories({query: "tmux-inject Shape A cleanup SwarmHeartbeatService idleOutNudge Sub-iii"})
• Empirical: git log --all --oneline -- ai/daemons/orchestrator/services/SwarmHeartbeatService.mjs ai/scripts/lifecycle/idleOutNudge.mjs learn/agentos/wake-substrate/