## Why
Saved threads need to resume after a managed daemon restart so active goals can continue without waiting for a client to reconnect.
## What changed
- Consume the recovery snapshot at startup and restore threads in the background through the shared cold-resume path.
- Trigger idle lifecycle work without attaching a client subscription, and leave already-loaded threads untouched.
- Continue recovery after individual thread failures and abort background recovery during shutdown.
## Testing
Extend the daemon restart integration test to verify goal continuation before client reconnection, restored conversation history and tools, idle-thread restoration, and recovery snapshot consumption. Include malformed snapshots and an invalid thread ID.
GitOrigin-RevId: 90e7b8f74ddc0ae327bacde1b2108b9749c65f2a