Closes #11. ## Summary - Serve Django admin on LAN IP `10.0.0.128` (not `piha.li`). Compose now publishes `0.0.0.0:8005` and passes `SHORT_ADMIN_HOSTS` into the container. - Admin index has a campaign mint form: domain, campaign, source, metric. Save builds `https://{domain}/?utm_campaign=&utm_source=&utm_medium=` (metric) and shows a copyable short URL. - Public `/admin/` on `piha.lc` / `piha.li` stays 404. ## Test plan - [ ] `cd site && uv run python manage.py test` - [ ] Recreate compose (`docker compose up --build`) so `WEB_BIND` / `SHORT_ADMIN_HOSTS` take effect - [ ] From another LAN machine: `http://10.0.0.128:8005/admin/` (staff login) shows the mint form - [ ] Save a link for an allowlisted domain, copy the short URL, confirm it 302s - [ ] `https://piha.li/admin` still 404 Reviewed-on: #12