fix: clean up worker and run state on daemon shutdown

[danielkov]

Summary

• shutdown_all now marks workers as stopped and cancels active runs in the DB before exiting, matching what stop_worker already does for individual workers.

Daemon shutdown now cleans up worker and run state

Previously, when the granary daemon shut down (via granary daemon stop, signals, or any other reason), workers were signalled to stop but their database status was never updated. This left workers permanently marked as running in the global database with their active runs also stuck in running state.

On next daemon start, restore_workers would find these stale "running" workers and attempt to respawn them — potentially picking up orphaned runs from completely unrelated workspaces. Manually stopping individual workers worked correctly because stop_worker properly updated the DB, but the bulk shutdown_all path (used on daemon exit) skipped this cleanup entirely.

shutdown_all now mirrors the same cleanup that stop_worker does: after signalling and waiting for workers to finish, it marks each worker as stopped and cancels any active runs in the database.

✻ Clauded...