## Why
Managed app-server shutdowns use a fixed 60-second grace period. Allow users to adjust how long shutdown waits before forcing the process to exit.
## What changed
- Add `shutdownGraceSeconds` to daemon settings, accepting integers from 0 through 300 and defaulting to 60. Zero requests graceful shutdown and then forces termination immediately.
- Apply the setting to managed app-server stops and restarts, including updater-triggered restarts, and extend the lifecycle lock timeout to accommodate the maximum grace period.
- Keep `stop` usable with unreadable or invalid settings by falling back to the default grace period.
## Testing
Add tests for setting defaults and bounds, invalid-value fallback, preservation when saving remote-control settings, graceful process exit, and forced termination with zero or finite grace periods.
GitOrigin-RevId: 8627b391323cf27b40df96935a82e66aa715f572
Eric Traut
a51608398d