fix(ci): Add Docker login step for Harbor authentication

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.github/workflows/deploy-prod.yml

@@ -85,13 +85,10 @@ jobs:
           echo "web_image=${{ env.REGISTRY }}/${{ env.HARBOR_PROJECT }}/web:${TAG}" >> $GITHUB_OUTPUT
           echo "📦 Image Tag: ${TAG}"
 
-      - name: Verify Docker Auth
+      - name: Login to Harbor Registry
         run: |
-          if docker pull ${{ env.REGISTRY }}/library/hello-world:latest 2>/dev/null || true; then
-            echo "✅ Harbor 認證有效"
-          else
-            echo "⚠️ Harbor 認證可能需要更新"
-          fi
+          echo "${{ secrets.HARBOR_PASSWORD }}" | docker login ${{ env.REGISTRY }} -u ${{ secrets.HARBOR_USER }} --password-stdin
+          echo "✅ Harbor 登入成功"
 
       # ----- Build API Image -----
       # Phase 6.4i: 必須從 monorepo 根目錄建構 (context: .)