fix(docker): push to Docker Hub with DOCKER_USERNAME/DOCKER_TOKEN secrets

Author: swadhinbiswas

.github/workflows/ci.yml

@@ -327,18 +327,18 @@ jobs:
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
 
-      - name: Login to Container Registry
+      - name: Login to Container Registry (Docker Hub)
         uses: docker/login-action@v3
         with:
-          registry: ghcr.io
-          username: ${{ github.actor }}
-          password: ${{ secrets.GITHUB_TOKEN }}
+          registry: docker.io
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_TOKEN }}
 
       - name: Extract metadata
         id: meta
         uses: docker/metadata-action@v5
         with:
-          images: ghcr.io/${{ github.repository }}
+          images: ${{ secrets.DOCKER_USERNAME }}/opencodehub
           tags: |
             type=ref,event=branch
             type=sha