fix: use docker login CLI instead of login-action for Gitea compat

docker/login-action@v3 fails with 'Username and password required' on
Gitea Actions — secrets not passed to action with: inputs. Switch to
direct docker login CLI which reliably interpolates secrets in run: steps.

.gitea/workflows/build-push.yaml

@@ -9,8 +9,8 @@ on:
 env:
   NTFY_URL: http://ntfy.observability.svc.cluster.local:80
   GOPRIVATE: git.daviestechlabs.io
-  REGISTRY: gitea-http.gitea.svc.cluster.local:3000/daviestechlabs
+  REGISTRY: registry.lab.daviestechlabs.io/daviestechlabs
-  REGISTRY_HOST: gitea-http.gitea.svc.cluster.local:3000
+  REGISTRY_HOST: registry.lab.daviestechlabs.io
   IMAGE_NAME: voice-assistant
 
 jobs:
@@ -123,40 +123,13 @@ jobs:
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
-        with:
+
-          buildkitd-config-inline: |
+      - name: Login to Gitea Registry
-            [registry."gitea-http.gitea.svc.cluster.local:3000"]
+        run: echo "${{ secrets.REGISTRY_TOKEN }}" | docker login "${{ env.REGISTRY_HOST }}" -u "${{ secrets.REGISTRY_USER }}" --password-stdin
-              http = true
-              insecure = true
 
       - name: Login to Docker Hub
         if: vars.DOCKERHUB_USERNAME != ''
-        uses: docker/login-action@v3
+        run: echo "${{ secrets.DOCKERHUB_TOKEN }}" | docker login -u "${{ vars.DOCKERHUB_USERNAME }}" --password-stdin
-        with:
-          username: ${{ vars.DOCKERHUB_USERNAME }}
-          password: ${{ secrets.DOCKERHUB_TOKEN }}
-
-      - name: Configure Docker for insecure registry
-        run: |
-          sudo mkdir -p /etc/docker
-          echo '{"insecure-registries": ["${{ env.REGISTRY_HOST }}"]}' | sudo tee /etc/docker/daemon.json
-          sudo systemctl restart docker || sudo service docker restart || true
-          sleep 2
-
-      - name: Login to Gitea Registry
-        run: |
-          AUTH=$(echo -n "${{ secrets.REGISTRY_USER }}:${{ secrets.REGISTRY_TOKEN }}" | base64 -w0)
-          mkdir -p ~/.docker
-          cat > ~/.docker/config.json << EOF
-          {
-            "auths": {
-              "${{ env.REGISTRY_HOST }}": {
-                "auth": "$AUTH"
-              }
-            }
-          }
-          EOF
-          echo "Auth configured for ${{ env.REGISTRY_HOST }}"
 
       - name: Extract metadata
         id: meta
@@ -175,8 +148,7 @@ jobs:
           push: true
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
-          cache-from: type=gha
+
-          cache-to: type=gha,mode=max
 
   notify:
     name: Notify