feat: add VPS Monitor backend and frontend services

- Create systemd service for VPS Monitor agent.
- Add FastAPI backend with endpoints for managing VPS configurations and statuses.
- Implement Dockerfile for backend service with required dependencies.
- Create frontend using React with Vite and Tailwind CSS for styling.
- Add API client for communicating with the backend.
- Implement components for displaying VPS information and logs.
- Set up Docker Compose for orchestrating backend and frontend services.
- Add environment configuration files for backend and agent.
- Implement CORS support in the backend for frontend communication.

vps-monitor/agent/agent.service

@@ -0,0 +1,16 @@
+[Unit]
+Description=VPS Monitor Agent
+After=docker.service
+Requires=docker.service
+
+[Service]
+Type=simple
+User=root
+WorkingDirectory=/opt/vps-monitor-agent
+EnvironmentFile=/opt/vps-monitor-agent/.env
+ExecStart=/opt/vps-monitor-agent/venv/bin/uvicorn agent:app --host 0.0.0.0 --port 8001
+Restart=always
+RestartSec=5
+
+[Install]
+WantedBy=multi-user.target