ci: fix registry login - skip on PRs, add Docker Hub auth

- Only login to Gitea registry on push (not PRs)
- Add optional Docker Hub login to avoid pull rate limits
- Requires REGISTRY_USER, REGISTRY_TOKEN secrets in Gitea
- Optional: DOCKERHUB_USERNAME (var) + DOCKERHUB_TOKEN (secret)

.gitea/workflows/build-push.yaml

@@ -30,7 +30,17 @@ jobs:
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
 
+      # Login to Docker Hub to avoid pull rate limits
+      - name: Login to Docker Hub
+        if: vars.DOCKERHUB_USERNAME != ''
+        uses: docker/login-action@v3
+        with:
+          username: ${{ vars.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      # Only login to Gitea when pushing (not PRs) and secrets are available
       - name: Login to Gitea Registry
+        if: github.event_name != 'pull_request'
         uses: docker/login-action@v3
         with:
           registry: git.daviestechlabs.io
@@ -70,7 +80,15 @@ jobs:
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
 
+      - name: Login to Docker Hub
+        if: vars.DOCKERHUB_USERNAME != ''
+        uses: docker/login-action@v3
+        with:
+          username: ${{ vars.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
       - name: Login to Gitea Registry
+        if: github.event_name != 'pull_request'
         uses: docker/login-action@v3
         with:
           registry: git.daviestechlabs.io
@@ -110,7 +128,15 @@ jobs:
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
 
+      - name: Login to Docker Hub
+        if: vars.DOCKERHUB_USERNAME != ''
+        uses: docker/login-action@v3
+        with:
+          username: ${{ vars.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
       - name: Login to Gitea Registry
+        if: github.event_name != 'pull_request'
         uses: docker/login-action@v3
         with:
           registry: git.daviestechlabs.io
@@ -150,7 +176,15 @@ jobs:
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
 
+      - name: Login to Docker Hub
+        if: vars.DOCKERHUB_USERNAME != ''
+        uses: docker/login-action@v3
+        with:
+          username: ${{ vars.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
       - name: Login to Gitea Registry
+        if: github.event_name != 'pull_request'
         uses: docker/login-action@v3
         with:
           registry: git.daviestechlabs.io