- Add back buttons to MachinesPage and SpawnPage for non-Telegram environments
- Fix navigation after session creation to clear spawn flow from history
- Update useAppGoBack hook to use explicit path navigation for consistent behavior
Replace state-based screen navigation with proper URL-based routing. This includes:
- New router configuration with routes for sessions, machines, and spawn pages
- App context provider to share API and token across the app
- useAppGoBack hook for handling browser and Telegram back navigation
- Refactored App component to render outlet and use router hooks
- Memory history for Telegram app, browser history for web