- Add browser-based Web UI with real-time WebSocket updates
- Extract business logic into Controller layer (Probe, Milling, ToolChange)
- Introduce IMachine interface for testability
- Add comprehensive unit test suite
- Refactor jog keys to WASD, improve preflight validation
- Auto-apply probe data when loading complete probe grid
- Add safety retract before probe traversal
- Unify force disconnect handling for TUI and web clients

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>