Add environment configuration and local development documentation

- Parameterize CORS_ORIGINS in docker-compose.swarm.yml
- Add .env.example with configuration options
- Create comprehensive LOCAL_DEVELOPMENT.md guide
- Update README.md with environment variable documentation
- Provide alternatives for local development without production domain

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

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

backend/requirements.txt

@@ -2,6 +2,7 @@
 fastapi==0.104.1
 uvicorn[standard]==0.24.0
 python-multipart==0.0.6
+gunicorn==21.2.0
 
 # Database
 sqlalchemy==2.0.23
@@ -16,6 +17,10 @@ aioredis==2.0.1
 # HTTP Clients
 aiohttp==3.9.1
 httpx==0.25.2
+requests==2.31.0
+
+# SSH Client for CLI Agents
+asyncssh==2.14.2
 
 # Authentication and Security
 python-jose[cryptography]==3.3.0
@@ -31,8 +36,9 @@ python-dotenv==1.0.0
 PyYAML==6.0.1
 orjson==3.9.10
 
-# WebSockets
+# WebSockets and Socket.IO
 websockets==12.0
+python-socketio==5.10.0
 
 # Monitoring and Metrics
 prometheus-client==0.19.0
@@ -41,6 +47,8 @@ prometheus-client==0.19.0
 python-dateutil==2.8.2
 click==8.1.7
 rich==13.7.0
+psutil==5.9.6
+markdown==3.5.1
 
 # Development
 pytest==7.4.3