Fix Django Production Deployment Errors

My Django app has been running smoothly in development, but I hit two snags on the production server and need them ironed out quickly.

1. Inside my virtualenv I installed `django-environ` with a plain `pip install`, yet the app crashes on startup with:
`ModuleNotFoundError: No module named 'environ'`.
The package shows up in `pip list`, and the virtual environment is definitely activated.

2. I created `/etc/systemd/system/gunicorn.service` to launch Gunicorn, but `systemctl start gunicorn` returns “file not found.” The service file exists and points to the correct virtual-environment Gunicorn binary.

I’d like you to:
• trace and eliminate the missing-module error so the project imports `environ` without issue;
• diagnose the Gunicorn service path problem, adjust the unit file if needed, reload systemd and verify the socket starts cleanly;
• leave me with concise notes on what you changed (paths, permissions, additional packages, etc.) so I can replicate the fix on staging.

SSH access is ready, and I can restart services or provide logs on request. Looking forward to getting the project back online fast.