Review Zig Kuka Arm robot architecture

[saint0x]

Backend (Zig):

• Enable 1kHz joint state streaming (was disabled)
• Enable 100Hz collision detection updates (was disabled)
• Fix system status to 100Hz (was 10Hz)
• Add graceful shutdown with SIGINT/SIGTERM signal handlers
• Fix getRobotState() to return actual state based on conditions
• Fix setTorques() to correctly set torque control mode
• Add SafetyMonitor.enable(), disable(), emergencyStop() methods
• Improve error handling in communication loop

Frontend (React/Vite):

• Fix package.json: downgrade date-fns for compatibility, remove expo/react-native
• Pin React Three Fiber versions for stability
• Fix protocol mismatch: convert backend numeric state to frontend string enums
• Remove mock physics simulation, use backend authority
• Connect robot visualization to actual backend joint positions
• Implement command sending when user changes angles or presets
• Add proper TypeScript interfaces for backend communication
• Update control panel with temperature display and status indicators

Integration:

• Complete bidirectional data flow between frontend and backend
• Target angles (user input) vs actual angles (backend) separation
• Automatic fallback to target angles when backend disconnected
• Proper WebSocket reconnection handling

Documentation:

• Update CLAUDE.md to reflect Vite setup (was incorrectly showing Next.js)
• Update FE.md with implementation status and architecture diagram
• Add data flow documentation