Create systemd service file for DevMate service

[OhmSpectator]

We need to create a systemd service file to manage the devmate service. This service file should enable us to start, stop, and restart the devmate application automatically at system boot or manually when needed. The service should ensure that the application's dependencies, particularly its virtual environment, are correctly handled.

Requirements

• The systemd service must be able to start the devmate service using the Makefile's run target.
• It should ensure that the virtual environment is activated correctly, or the correct Python interpreter and dependencies are used without needing to activate the venv.
• The service should support the standard start, stop, and restart commands.
• It must include error handling to ensure that if the service fails to start, it provides clear logging or feedback for troubleshooting.

Implementation Details

• Environment variables needed by devmate should be correctly handled, either through an EnvironmentFile or directly in the service file.
• Considerations should be made for any permissions or user-specific configurations needed for devmate to run correctly.