* feat: add crabwalk CLI
- bin/crabwalk: shell wrapper with start/stop/status/update commands
- daemon mode with --daemon flag
- auto-detect gateway token from ~/.clawdbot/clawdbot.json
- show network IPs on startup for remote access
- update skill.md and README with CLI usage
* auto-add ~/.local/bin to PATH during install
* support zsh PATH config