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>

server/routers/__init__.py

@@ -7,20 +7,24 @@ FastAPI routers for different API endpoints.
 
 from .agent import router as agent_router
 from .assistant_chat import router as assistant_chat_router
+from .devserver import router as devserver_router
 from .expand_project import router as expand_project_router
 from .features import router as features_router
 from .filesystem import router as filesystem_router
 from .projects import router as projects_router
 from .settings import router as settings_router
 from .spec_creation import router as spec_creation_router
+from .terminal import router as terminal_router
 
 __all__ = [
     "projects_router",
     "features_router",
     "agent_router",
+    "devserver_router",
     "spec_creation_router",
     "expand_project_router",
     "filesystem_router",
     "assistant_chat_router",
     "settings_router",
+    "terminal_router",
 ]