Add production WSGI server and CLAUDE.md documentation

- Replace Flask development server with Waitress production WSGI server
- Add waitress>=2.1.0 dependency to pyproject.toml and Makefile
- Configure 4-thread server for better performance and stability
- Create comprehensive CLAUDE.md guide for future development
- Document architecture, deployment, testing, and common patterns
- Update README.md with production-ready feature and dependencies

Eliminates Flask development server warning and provides production-grade
web serving suitable for Raspberry Pi deployment.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

rotary_phone_web.py

@@ -14,6 +14,7 @@ import numpy as np
 import threading
 from flask import Flask, render_template, request, send_file, jsonify, redirect, url_for
 from werkzeug.utils import secure_filename
+from waitress import serve
 import json
 import sys
 import zlib
@@ -1989,13 +1990,15 @@ def main():
     # Get and display local IP
     local_ip = get_local_ip()
     print("\n" + "="*60)
+    print(f"🚀 Wedding Phone System Starting...")
     print(f"Web Interface Available At:")
     print(f"  http://{local_ip}:{WEB_PORT}")
     print(f"  http://localhost:{WEB_PORT}")
     print("="*60 + "\n")
-    
-    # Start Flask web server
-    app.run(host='0.0.0.0', port=WEB_PORT, debug=False, threaded=True)
+
+    # Start production WSGI server (waitress)
+    print(f"Starting production server on 0.0.0.0:{WEB_PORT}")
+    serve(app, host='0.0.0.0', port=WEB_PORT, threads=4)
 
 if __name__ == "__main__":
     main()