build: script to publish web/worker images to the Gitea registry

Adds scripts/build-push.sh (build + push lyra-web/lyra-worker :latest and
:<sha> to git.jger.nl) + a README 'Deploying to a server (pre-built images)'
section. The server pulls these via the vm-download ops repo (docker/lyra).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

README.md

@@ -102,6 +102,29 @@ reach the live DB automatically. Enter Qobuz / Soulseek / Last.fm credentials in
 **Settings** (they persist across rebuilds), then follow an artist or request an album
 to feed The Floor.
 
+## Deploying to a server (pre-built images)
+
+For a server that should **pull** rather than build, the `web` and `worker` images are
+published to the Gitea container registry and consumed by a compose file in the
+[`vm-download`](https://git.jger.nl/Jonathan/vm-download) ops repo (`docker/lyra/`).
+
+Publish a new release from this repo (amd64):
+
+```sh
+docker login git.jger.nl          # once — Gitea user + a token with package:write
+./scripts/build-push.sh           # builds + pushes lyra-web / lyra-worker (:latest and :<sha>)
+```
+
+Then on the server:
+
+```sh
+cd /opt/git/vm-download && git pull
+cd docker/lyra && docker compose pull && docker compose up -d
+```
+
+`db` (Postgres) and `db-backup` use the stock `postgres:17` image, so only the two custom
+images are built here. See `docker/lyra/README.md` in the ops repo for first-time setup.
+
 ## Managing the library
 
 Open an album on the **Library** page and use **Delete album** to remove it: the folder is