- New `tunnel` command: expose localhost ports via Cloudflare quick tunnels
(`bu tunnel 3000` → trycloudflare.com URL, idempotent, auto-cleanup on session close)
- New `skills/remote-browser/SKILL.md`: guides sandboxed agents through
cloud browser + tunnel workflow
- TunnelInfo dataclass on SessionInfo for tunnel lifecycle management
- Tunnel dispatch in both SessionServer and CLI arg parser
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>