Implements detailed polecat status display including:
- Lifecycle state (working, done, stuck, idle)
- Assigned issue
- Session status (running/stopped, attached/detached)
- Session creation time
- Last activity time with relative "ago" format
Also extends tmux.SessionInfo and session.Info to include
last activity timestamp from tmux session_activity.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>