feat: add interactive terminal and dev server management

Add new features for interactive terminal sessions and dev server control:

Terminal Component:
- New Terminal.tsx component using xterm.js for full terminal emulation
- WebSocket-based PTY communication with bidirectional I/O
- Cross-platform support (Windows via winpty, Unix via built-in pty)
- Auto-reconnection with exponential backoff
- Fix duplicate WebSocket connection bug by checking CONNECTING state
- Add manual close flag to prevent auto-reconnect race conditions
- Add project tracking to avoid duplicate connects on initial activation

Dev Server Management:
- New DevServerControl.tsx for starting/stopping dev servers
- DevServerManager service for subprocess management
- WebSocket streaming of dev server output
- Project configuration service for reading package.json scripts

Backend Infrastructure:
- Terminal router with WebSocket endpoint for PTY I/O
- DevServer router for server lifecycle management
- Terminal session manager with callback-based output streaming
- Enhanced WebSocket schemas for terminal and dev server messages

UI Integration:
- New Terminal and Dev Server tabs in the main application
- Updated DebugLogViewer with improved UI and functionality
- Extended useWebSocket hook for terminal message handling

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

ui/package.json

@@ -14,6 +14,9 @@
     "@radix-ui/react-dropdown-menu": "^2.1.2",
     "@radix-ui/react-tooltip": "^1.1.3",
     "@tanstack/react-query": "^5.60.0",
+    "@xterm/addon-fit": "^0.11.0",
+    "@xterm/addon-web-links": "^0.12.0",
+    "@xterm/xterm": "^6.0.0",
     "canvas-confetti": "^1.9.4",
     "clsx": "^2.1.1",
     "lucide-react": "^0.460.0",