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>

.dockerignore

@@ -0,0 +1,71 @@
+# Git
+.git
+.gitignore
+
+# Python
+__pycache__
+*.pyc
+*.pyo
+*.pyd
+.Python
+venv/
+env/
+.venv
+pip-log.txt
+pip-delete-this-directory.txt
+.tox/
+.coverage
+.coverage.*
+.cache
+*.egg-info/
+.pytest_cache/
+
+# Node
+node_modules/
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# IDE
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+
+# OS
+.DS_Store
+.DS_Store?
+._*
+.Spotlight-V100
+.Trashes
+ehthumbs.db
+Thumbs.db
+
+# Project specific
+logs/
+*.log
+.env
+.env.*
+!.env.production
+*.db
+*.sqlite
+/tmp
+/temp
+test_*.py
+tests/
+
+# Documentation
+*.md
+!README.md
+docs/
+
+# CI/CD
+.github/
+.gitlab-ci.yml
+.travis.yml
+
+# Development files
+deploy.sh
+Makefile
+docker-compose.override.yml