ci(demo-service): move manifest to home-apps/ root for ArgoCD

- ArgoCD 'home-apps' app tracks the home-apps/ directory at root level only
- Move k8s-manifest.yaml to home-apps/demo-service.yaml (sibling of other apps)
- Keep source code (Dockerfile, service.py, etc.) in home-apps/demo-service/ subdirectory
- Update workflow to update the new path
- Also fix imagePullSecrets placement (pod-level not container-level)

.github/workflows/build-demo-service.yml

@@ -56,17 +56,17 @@ jobs:
           IMAGE="${{ steps.tag.outputs.full_image }}"
           echo "Updating manifest to: ${IMAGE}"
           # Match any demo-manager image reference (works for any current value)
-          sed -i "s|image: docker.io/library/demo-manager:.*|image: ${IMAGE}|" home-apps/demo-service/k8s-manifest.yaml
-          sed -i "s|image: ghcr.io/wahyd4/demo-manager:.*|image: ${IMAGE}|" home-apps/demo-service/k8s-manifest.yaml
-          sed -i "s|imagePullPolicy:.*|imagePullPolicy: Always|" home-apps/demo-service/k8s-manifest.yaml
+          sed -i "s|image: docker.io/library/demo-manager:.*|image: ${IMAGE}|" home-apps/demo-service.yaml
+          sed -i "s|image: ghcr.io/wahyd4/demo-manager:.*|image: ${IMAGE}|" home-apps/demo-service.yaml
+          sed -i "s|imagePullPolicy:.*|imagePullPolicy: Always|" home-apps/demo-service.yaml
           # Show what changed
-          git diff home-apps/demo-service/k8s-manifest.yaml || echo "No diff produced"
+          git diff home-apps/demo-service.yaml || echo "No diff produced"
 
       - name: Commit & push manifest update
         run: |
           git config user.name "github-actions[bot]"
           git config user.email "github-actions[bot]@users.noreply.github.com"
-          git add home-apps/demo-service/k8s-manifest.yaml
+          git add home-apps/demo-service.yaml
           if git diff --cached --quiet; then
             echo "No manifest changes to commit"
             exit 0