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/backend/Dockerfile

@@ -0,0 +1,6 @@
+FROM python:3.12-slim
+WORKDIR /app
+COPY requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
+COPY . .
+CMD ["uvicorn", "main:app", "--host", "0.0.0.0", "--port", "8000"]