Dogs can now reset their own state to idle after completing work:
gt dog done # Auto-detect from BD_ACTOR
gt dog done alpha # Explicit name
This solves the issue where dog sessions would complete work but remain in
"working" state because nothing processed the DOG_DONE mail. Now dogs can
explicitly mark themselves idle before handing off.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>