feat: renew workers from manager activity

[dataforxyz]

Summary

• renew the exact owned worker when an opt-in primary OpenCode manager receives that worker's message
• run the orchestrator's internal lifecycle heartbeat for checkpoint requests
• relay checkpoint requests through the OpenCode Intercom runtime
• avoid duplicate startup cleanup/timer reconfiguration in internal heartbeat and activity-renew paths
• expose acknowledge for terminal fleet forget operations

Why

The OpenCode primary manager uses the same orchestrator lifecycle as Pi but does not host the Pi extension event bus. This supplies equivalent manager-received activity and checkpoint behavior without enabling fleet authority inside owned workers.

Safety

• fleet management remains opt-in and disabled inside owned workers
• broker-stamped sender ID is passed to exact orchestrator renewal
• durable duplicate inbound messages do not renew twice
• manager sends do not count as worker activity

Verification

• npm run typecheck
• npm run build
• npm test — 70/70
• independent Fable review: APPROVE, no blockers

Coordinated with:

• agent-intercom-orchestrator feat/activity-gated-worker-lifecycle
• agent-intercom-pi feat/worker-activity-events

[dataforxyz]

Independent lifecycle review result: APPROVE — no blockers.

The reviewer confirmed exact-worker activity routing, cleanup/adopt fencing, disabled timer reconfiguration on internal paths, and manager-only fleet authority. Per-message subprocess/coalescing work is tracked separately in #3.