Add production WSGI server - Flask dev server unsuitable for production load

This adds a complete production deployment setup using Gunicorn as the WSGI server, replacing Flask's development server.

Key components:
- Gunicorn configuration with optimized worker settings
- Support for sync, threaded, and async (gevent) workers
- Automatic worker recycling to prevent memory leaks
- Increased timeouts for audio processing
- Production-ready logging and monitoring

Deployment options:
1. Docker/Docker Compose for containerized deployment
2. Systemd service for traditional deployment
3. Nginx reverse proxy configuration
4. SSL/TLS support

Production features:
- wsgi.py entry point for WSGI servers
- gunicorn_config.py with production settings
- Dockerfile with multi-stage build
- docker-compose.yml with full stack (Redis, PostgreSQL)
- nginx.conf with caching and security headers
- systemd service with security hardening
- deploy.sh automated deployment script

Configuration:
- .env.production template with all settings
- Support for environment-based configuration
- Separate requirements-prod.txt
- Prometheus metrics endpoint (/metrics)

Monitoring:
- Health check endpoints for liveness/readiness
- Prometheus-compatible metrics
- Structured logging
- Memory usage tracking
- Request counting

Security:
- Non-root user in Docker
- Systemd security restrictions
- Nginx security headers
- File permission hardening
- Resource limits

Documentation:
- Comprehensive PRODUCTION_DEPLOYMENT.md
- Scaling strategies
- Performance tuning guide
- Troubleshooting section

Also fixed memory_manager.py GC stats collection error.

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

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

memory_manager.py

@@ -157,8 +157,10 @@ class MemoryManager:
                 stats.active_sessions = len(self.app.session_manager.sessions)
             
             # GC stats
-            for i in range(gc.get_count()):
-                stats.gc_collections[i] = gc.get_stats()[i].get('collections', 0)
+            gc_stats = gc.get_stats()
+            for i, stat in enumerate(gc_stats):
+                if isinstance(stat, dict):
+                    stats.gc_collections[i] = stat.get('collections', 0)
             
         except Exception as e:
             logger.error(f"Error collecting memory stats: {e}")