feat(ci): add timestamp-based image tags with commit hash

Push images with versioned tags in format TIMESTAMP-COMMIT and
frontend-TIMESTAMP-COMMIT for better traceability and rollback support.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

.gitlab-ci.yml

@@ -4,7 +4,6 @@ stages:
 variables:
   DOCKER_DRIVER: overlay2
   DOCKER_TLS_CERTDIR: "/certs"
-  IMAGE_TAG: $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG
   LATEST_TAG: $CI_REGISTRY_IMAGE:latest
 
 build-and-push:
@@ -15,14 +14,23 @@ build-and-push:
   before_script:
     - echo "Logging into GitLab Container Registry..."
     - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
+    # Generate timestamp and short commit hash for tags
+    - export TIMESTAMP=$(date -u +%Y%m%d%H%M%S)
+    - export SHORT_COMMIT=$(echo $CI_COMMIT_SHA | cut -c1-7)
+    - export VERSIONED_TAG=$CI_REGISTRY_IMAGE:${TIMESTAMP}-${SHORT_COMMIT}
+    - export FRONTEND_TAG=$CI_REGISTRY_IMAGE:frontend-${TIMESTAMP}-${SHORT_COMMIT}
   script:
     - echo "Building Docker image..."
-    - docker build -t $IMAGE_TAG -t $LATEST_TAG .
+    - docker build -t $VERSIONED_TAG -t $FRONTEND_TAG -t $LATEST_TAG .
     - echo "Pushing Docker image to registry..."
-    - docker push $IMAGE_TAG
+    - docker push $VERSIONED_TAG
+    - docker push $FRONTEND_TAG
     - docker push $LATEST_TAG
     - echo "Build and push completed successfully!"
-    - echo "Image available at $IMAGE_TAG"
+    - echo "Images available at:"
+    - echo "  $VERSIONED_TAG"
+    - echo "  $FRONTEND_TAG"
+    - echo "  $LATEST_TAG"
   rules:
     - if: $CI_COMMIT_BRANCH == "main"
       when: always