Roundcube as its own image built by the workflow (no config file or newer Compose needed)

- roundcube/: official Roundcube plus hub.php settings
- workflow builds and pushes git.necloud.us/nate/hub-roundcube, and runs the player and webmail tests
- compose uses the image instead of an inline config

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

.gitea/workflows/build.yml

@@ -20,6 +20,8 @@ jobs:
       - run: node tools/smoke-test.js
       - run: node tools/users-test.js   # accounts: private data, tab limits, invites, migration
       - run: node tools/plex-test.js    # Plex sign-in stays signed in and repairs itself
+      - run: node tools/player-test.js  # music player: queue, shuffle/repeat, stall recovery
+      - run: node tools/webmail-test.js # the /webmail/ pass-through to Roundcube
 
       - uses: docker/setup-buildx-action@v3
 
@@ -50,3 +52,21 @@ jobs:
           labels: ${{ steps.meta.outputs.labels }}
           cache-from: type=registry,ref=git.necloud.us/nate/hub:buildcache
           cache-to: type=registry,ref=git.necloud.us/nate/hub:buildcache,mode=max
+
+      # The webmail container (official Roundcube + the hub's settings)
+      - id: meta_rc
+        uses: docker/metadata-action@v5
+        with:
+          images: git.necloud.us/nate/hub-roundcube
+          tags: |
+            type=raw,value=latest,enable={{is_default_branch}}
+            type=sha,format=short
+            type=ref,event=tag
+
+      - uses: docker/build-push-action@v6
+        with:
+          context: ./roundcube
+          platforms: linux/amd64
+          push: true
+          tags: ${{ steps.meta_rc.outputs.tags }}
+          labels: ${{ steps.meta_rc.outputs.labels }}