docs: point to pre-built Docker Hub image in README and docker-compose

- docker-compose.yml: changed from build: . to image: droideparanoico/dostalgia
- README: simplified quick start to pull instead of build
- README: added link to Docker Hub repo with CI note

README.md

@@ -89,7 +89,7 @@ IGDB features degrade gracefully — if credentials aren't set, uploads and meta
 cp .env.example .env
 # Edit .env with your Twitch credentials (see IGDB section below)
 
-# 2. Build & run
+# 2. Pull & run
 docker compose up -d
 ```
 
@@ -98,13 +98,14 @@ Open http://localhost:8765
 ### With Docker
 
 ```bash
-docker build -t dostalgia .
 docker run -p 8765:8765 -v $(pwd)/data:/data \
   -e TWITCH_CLIENT_ID=your_id \
   -e TWITCH_CLIENT_SECRET=your_secret \
-  dostalgia
+  droideparanoico/dostalgia
 ```
 
+The pre-built image is published to Docker Hub as [`droideparanoico/dostalgia`](https://hub.docker.com/r/droideparanoico/dostalgia). Published automatically on every GitHub release via CI.
+
 ## Development (without Docker)
 
 Terminal 1 — Frontend dev server: