fix: bypass docker login, pre-populate auth config for HTTP registry push

.gitea/workflows/build.yml

@@ -112,7 +112,12 @@ jobs:
       - name: Push to registry
         if: env.REGISTRY != ''
         run: |
-          echo "${{ secrets.REGISTRY_PASSWORD }}" | docker login ${{ env.REGISTRY }} -u "${{ secrets.REGISTRY_USERNAME }}" --password-stdin
+          # docker login sends POST /auth to Podman which incorrectly tries HTTPS even for
+          # insecure registries. Pre-populate config.json instead — docker push goes through
+          # the Podman daemon which correctly uses HTTP (insecure=true in registries.conf).
+          mkdir -p ~/.docker
+          AUTH=$(echo -n "${{ secrets.REGISTRY_USERNAME }}:${{ secrets.REGISTRY_PASSWORD }}" | base64 -w 0)
+          echo "{\"auths\":{\"${{ env.REGISTRY }}\":{\"auth\":\"${AUTH}\"}}}" > ~/.docker/config.json
           docker push "${{ steps.image.outputs.full }}"
 
       - name: Save image to file