feat: Add Python launcher script for easy application startup

Added comprehensive application launcher:
- app.py - Python script to start both backend and frontend
- start.bat - Windows batch file wrapper
- START_HERE.md - Quick start guide with troubleshooting
- Updated package.json with 'npm start' command

Features:
✅ Pre-flight checks (Node.js, npm, dependencies, .env)
✅ Starts both backend (port 3001) and frontend (port 5173)
✅ Colored terminal output with status messages
✅ Process monitoring and health checks
✅ Graceful shutdown with Ctrl+C
✅ Cross-platform support (Windows/Linux/Mac)
✅ Automatic cleanup of child processes

Usage:
  python app.py
  OR
  npm start
  OR (Windows only)
  start.bat

Benefits:
- Single command to start entire application
- No need for multiple terminal windows
- Automatic error detection and reporting
- User-friendly colored output
- Test account information displayed on startup
- Easy for non-technical users

Documentation:
- START_HERE.md provides complete quick start guide
- Includes troubleshooting section
- Lists all access points and test accounts

🤖 Generated with Claude Code
Co-Authored-By: Claude <noreply@anthropic.com>

package.json

@@ -4,6 +4,7 @@
   "description": "5 Why Root Cause Analysis Tool with Ollama API Integration",
   "type": "module",
   "scripts": {
+    "start": "python app.py",
     "dev": "concurrently \"npm run server\" \"npm run client\"",
     "server": "node server.js",
     "client": "vite",