docker updates.

README.md

@@ -68,9 +68,19 @@ The app reads its settings from environment variables.
 The recommended way to run the project is with Docker Compose.
 
 ```bash
-docker-compose up --build
+npm run docker:up
 ```
 
+The main Compose file now uses the published Docker image and still reads values from the repository `.env` file. `DB_HOST` comes from that file for the app containers, so you can point the web UI and player at an external database host or change it to `mysql` if you want to use the bundled MySQL service.
+
+If you only want to test the image build from the current checkout without using Compose, run:
+
+```bash
+npm run docker:build
+```
+
+To publish the Docker image to the Gitea container registry, push to `main` or create a `v*` tag. The workflow in [.gitea/workflows/docker-publish.yml](.gitea/workflows/docker-publish.yml) builds `git.lzstealth.com/LZStealth/pulse-signage` and pushes `latest`, `sha`, and tagged releases.
+
 This starts:
 
 - the web admin app on port `3000`
@@ -79,6 +89,8 @@ This starts:
 
 The web app and player app share the same uploaded media volume, so files uploaded in the admin UI are available to the player.
 
+If you want to stop the stack later, run `npm run docker:down`. To follow logs, run `npm run docker:logs`.
+
 ## Important Notes
 
 - The web app must be able to reach the player through `PLAYER_INTERNAL_BASE_URL`.