fix: start scripts now validate prerequisites and stop on failure

- Check for Python and Node.js before starting
- Stop with clear error message if pip install fails
- Recommend Python 3.10-3.12 (3.13+ has compatibility issues)
- Show version info at startup for easier debugging
- Updated README with Python version guidance

start.bat

@@ -5,28 +5,82 @@ echo ===================================================
 echo     S H A D O W B R O K E R   --   STARTUP
 echo ===================================================
 echo.
-echo Installing backend dependencies if needed...
+
+:: Check for Python
+where python >nul 2>&1
+if %errorlevel% neq 0 (
+    echo [!] ERROR: Python is not installed or not in PATH.
+    echo [!] Install Python 3.10-3.12 from https://python.org
+    echo [!] IMPORTANT: Check "Add to PATH" during install.
+    echo.
+    pause
+    exit /b 1
+)
+
+:: Check Python version
+for /f "tokens=2 delims= " %%v in ('python --version 2^>^&1') do set PYVER=%%v
+echo [*] Found Python %PYVER%
+
+:: Check for Node.js
+where npm >nul 2>&1
+if %errorlevel% neq 0 (
+    echo [!] ERROR: Node.js/npm is not installed or not in PATH.
+    echo [!] Install Node.js 18+ from https://nodejs.org
+    echo.
+    pause
+    exit /b 1
+)
+
+for /f "tokens=1 delims= " %%v in ('node --version 2^>^&1') do echo [*] Found Node.js %%v
+
+echo.
+echo [*] Setting up backend...
 cd backend
 if not exist "venv\" (
-    echo Creating Python virtual environment...
+    echo [*] Creating Python virtual environment...
     python -m venv venv
+    if %errorlevel% neq 0 (
+        echo [!] ERROR: Failed to create virtual environment.
+        pause
+        exit /b 1
+    )
 )
 call venv\Scripts\activate.bat
+echo [*] Installing Python dependencies (this may take a minute)...
 pip install -r requirements.txt
+if %errorlevel% neq 0 (
+    echo.
+    echo [!] ERROR: pip install failed. See errors above.
+    echo [!] If you see Rust/cargo errors, your Python version may be too new.
+    echo [!] Recommended: Python 3.10, 3.11, or 3.12.
+    echo.
+    pause
+    exit /b 1
+)
+echo [*] Backend dependencies OK.
 cd ..
 
 echo.
-echo Installing frontend dependencies if needed...
+echo [*] Setting up frontend...
 cd frontend
 if not exist "node_modules\" (
-    echo Running npm install...
+    echo [*] Installing frontend dependencies...
     call npm install
+    if %errorlevel% neq 0 (
+        echo [!] ERROR: npm install failed. See errors above.
+        pause
+        exit /b 1
+    )
 )
+echo [*] Frontend dependencies OK.
 
 echo.
-echo Starting both services...
-echo (Press Ctrl+C to stop the dashboard)
+echo ===================================================
+echo   Starting services...
+echo   Dashboard: http://localhost:3000
+echo   Keep this window open! Initial load takes ~10s.
+echo ===================================================
+echo   (Press Ctrl+C to stop)
 echo.
 
-:: Start the dev server which runs both NEXT and API via concurrently
 call npm run dev