[TheGreatAxios]

Summary

• Stock Interchange has no undeploy route, so a reaper workflow can't exist yet (upstream ask tracked separately). Idle hibernation is now the sidecar's own decision: apps/sidecar/src/workflow-host-wiring/index.ts stamps a per-run last-activity clock on every inbound mail frame it dispatches, and its own sweep tears an idle run down with the same state-preserving IDLE_HIBERNATE_UNDEPLOY_REASON flavor the hub used to drive, once the run has been idle past the new CHAT_IDLE_HIBERNATE_MS sidecar env threshold (arktype-parsed alongside the other sidecar timing knobs).
• packages/agent-lifecycle is deleted. Chat's wake-on-mail path (wakeByAddressBounded in packages/chat/src/platform-adapter.ts) keeps its own small pendingWakes coalescing map inline, so the CL-7214 concurrent-wake protection is unchanged; the idle-sleep tracking half of the old package (track/untrack/recordActivity, the hub's chatIdleReapMs/HUB_CHAT_IDLE_REAP_MS knob, chatPlatform.recordActivity) is gone since nothing drives it from the hub anymore. Wake-on-mail relaunch behavior is otherwise unchanged.
• Cut every caller: packages/chat, packages/agent-directory's one-shot prompt runner (its lifecycle hook was unused by any caller), apps/hub (config knob, wiring, comments), package.json deps, tsconfig references (regenerated via bun scripts/generate-tsconfig-references.ts), and the report-error baseline entry the deleted package owned.

Deleted tests

Per this hard-cutover ruling, the following were deleted rather than adapted, since they encoded the old hub-driven idle-sweep behavior that no longer exists in chat:

• packages/chat/test/platform-adapter.test.ts: the describe("lifecycle wiring", ...) idle-sweep tests (busy-guard, idle-reap, idle-reap-then-relaunch regression pin, and the two "installs a sweep interval" tests), and the duplicate "...when lifecycle is configured" variant of the relaunch test (the "...is not configured" variant was kept and renamed, since that's the only remaining code path).
• packages/agent-directory/src/one-shot-prompt.test.ts: the createFakeLifecycle fixture and its track/recordActivity/untrack assertions (the lifecycle hook was dead code — nothing ever passed it in production).

Test plan

• bun run typecheck
• bun run lint
• bun run check:structural
• bun --cwd apps/sidecar test
• bun --cwd packages/agent-directory test
• bun --cwd packages/chat test
• bun --cwd apps/hub test

[linear-code]

CL-8187