feat(docker): enhance Docker deployment setup and configuration

Add comprehensive Docker deployment configuration with:
- New .dockerignore and .llm.env.example files
- Enhanced Dockerfile with multi-stage build and optimizations
- Detailed README with setup instructions and environment configurations
- Improved requirements.txt with Gunicorn
- Better error handling in async_configs.py

BREAKING CHANGE: Docker deployment now requires .llm.env file for API keys

tests/docker/test_docker.py

@@ -164,7 +164,7 @@ async def main():
     """Run all tests"""
     # Test direct API
     print("Testing direct API calls...")
-    # await test_direct_api()
+    await test_direct_api()
 
     # Test client SDK
     print("\nTesting client SDK...")