Authored by Claude Opus 4.7 (Claude Code). Session 5572d9a5-558d-4bea-b416-e31496c289c4.

FAIR-band: in-band [verify @ merge-gate]

Resolves #11859

Summary

Sub 16 of Epic #11831. Pure function in scheduling/<task>.mjs, matching the shape Sub 15 (PR #11863) established after 6 iterations of KISS pressure. Applies all Sub-15 lessons from the start — zero iteration overhead this round.

Evidence: L1 (4/4 pure-function unit tests pass) → L1 required for pure extraction (no behavioral change at orchestrator surface; new file is not wired in this Sub — Sub 18 #11862 owns the registry integration).

Sub-15 lessons applied from the start

• File at ai/daemons/orchestrator/scheduling/swarmHeartbeat.mjs (no Service/Coordinator suffix — pure function, not a service)
• One JSDoc block above the one function (no file-level + function-level split)
• No class extends Base, no singleton: true config, no Neo.gatekeep (zero Neo class-system features used)
• No decay-prone JSDoc references (no v13-path.md:N, no section labels like D3.1, no neighboring-file method names)
• Spec doesn't import Neo bootstrap (no module-load gatekeep call requiring globalThis.Neo)
• Function signature parallel to scheduling/dream.mjs for consistency

Strict boundary preserved

• SwarmHeartbeatService retains initAsync() + pulse() + all lifecycle/execution methods unchanged
• Orchestrator's inline schedule logic (Orchestrator.mjs:906-934) is NOT modified yet — Sub 18 #11862 wires the new projection into the registry
• The enabled-gate (this.swarmHeartbeatEnabled) stays in Orchestrator's call-site for now; Sub 18 will move profile-aware filtering into pickNextCandidate

Test Evidence

npm run test-unit -- test/playwright/unit/ai/daemons/orchestrator/scheduling/swarmHeartbeat.spec.mjs → 4/4 pass (507ms)

Test coverage:

• Interval-elapsed returns trigger
• Interval-not-elapsed returns null
• intervalMs <= 0 disabled (both 0 and negative)
• Missing state graceful (lastRunAt defaults to 0)

Post-Merge Validation

• Operator confirms no regression in swarm-heartbeat scheduling (new file exists but not wired; should be no observable change)

Deltas from ticket

• File location updated to scheduling/swarmHeartbeat.mjs (no Service/Coordinator suffix) per operator's KISS feedback on PR #11863
• Ticket title still references SwarmHeartbeatCoordinatorService — title naming churn deferred

Depends on

Epic #11831 (parent). Independent of Sub 15 #11858 (already merged); parallel-safe with Sub 17 #11860.

Unblocks

Sub 18 #11862.

Authority

Discussion #11857 Cycle-3.5 GPT [GRADUATION_APPROVED] + operator architectural ratify + operator KISS feedback on PR #11863 (scheduling/.mjs pure-function pattern).

Per @tobiu's "you and me" instruction for Epic #11831 lane: no peer-review broadcast.