feat(dashboard): Enhanced chat, spec management, and Claude integration

Backend:
- spec.py: New AtomizerSpec REST API endpoints
- spec_manager.py: SpecManager service for unified config
- interview_engine.py: Study creation interview logic
- claude.py: Enhanced Claude API with context
- optimization.py: Extended optimization endpoints
- context_builder.py, session_manager.py: Improved services

Frontend:
- Chat components: Enhanced message rendering, tool call cards
- Hooks: useClaudeCode, useSpecWebSocket, improved useChat
- Pages: Updated Dashboard, Analysis, Insights, Setup, Home
- Components: ParallelCoordinatesPlot, ParetoPlot improvements
- App.tsx: Route updates for canvas/studio

Infrastructure:
- vite.config.ts: Build configuration updates
- start/stop-dashboard.bat: Script improvements

atomizer-dashboard/start-dashboard.bat

@@ -25,6 +25,18 @@ if not exist "%CONDA_PATH%\Scripts\activate.bat" (
     exit /b 1
 )
 
+:: Stop any existing dashboard processes first
+echo [0/3] Stopping existing processes...
+taskkill /F /FI "WINDOWTITLE eq Atomizer Backend*" >nul 2>&1
+taskkill /F /FI "WINDOWTITLE eq Atomizer Frontend*" >nul 2>&1
+for /f "tokens=5" %%a in ('netstat -ano ^| findstr :%BACKEND_PORT% ^| findstr LISTENING') do (
+    taskkill /F /PID %%a >nul 2>&1
+)
+for /f "tokens=5" %%a in ('netstat -ano ^| findstr :%FRONTEND_PORT% ^| findstr LISTENING') do (
+    taskkill /F /PID %%a >nul 2>&1
+)
+ping 127.0.0.1 -n 2 >nul
+
 echo [1/3] Starting Backend Server (port %BACKEND_PORT%)...
 start "Atomizer Backend" cmd /k "call %CONDA_PATH%\Scripts\activate.bat %CONDA_ENV% && cd /d %SCRIPT_DIR%backend && python -m uvicorn api.main:app --reload --port %BACKEND_PORT%"