fix(deploy): use datum container dns

README.md

@@ -46,7 +46,12 @@ Allowlist of npubs is set via `NOSTR_ALLOWED_NPUBS`. Anything else is rejected b
    - Repository URL: `https://git.tx1138.com/lfg2025/gashboard`
    - Compose path: `docker-compose.yml`
    - Add env vars (see `.env.example`)
-   - Set the `external` network in the compose file to match your Datum app's docker network (find with `docker network ls` on the Umbrel)
+   - Set `DATUM_NETWORK` to the network attached to `datum_datum_1`:
+     ```bash
+     docker inspect -f '{{range $name, $_ := .NetworkSettings.Networks}}{{$name}}{{"\n"}}{{end}}' datum_datum_1
+     ```
+   - On Umbrel this is usually `umbrel_main_network`, which is the compose default.
+   - Leave `DATUM_URL` unset unless you need to override it. The default is `http://datum_datum_1:21000`, which avoids Umbrel's host proxy and stale container IPs.
 
 4. Open the dashboard, log in with one of the allowed npubs, watch your boards lose at hashing in style.