Implements agent parking and resumption on gates:
- gt park <gate-id>: Parks work on a gate, saves context
- gt resume: Checks for cleared gates and restores work
- gt gate wake: Sends wake mail to waiters when gate closes
These commands enable agents to safely suspend work while waiting
for external conditions (timers, CI, human approval) and resume
when gates clear.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
