ci: prevent empty cicd-base tag in workflow

.gitea/workflows/cicd.yml

@@ -47,6 +47,11 @@ jobs:
         run: |
           echo "=== Checking if CICD Base Image Needs Rebuilding ==="
 
+          # Always compute hash first so downstream steps have a valid tag.
+          BASE_HASH=$(sha256sum Dockerfile.cicd-base | cut -d' ' -f1 | head -c16)
+          echo "Base Dockerfile hash: ${BASE_HASH}"
+          echo "base_hash=${BASE_HASH}" >> $GITHUB_OUTPUT
+
           # Login to registry to check for existing image
           if echo "${PACKAGE_ACCESS_TOKEN}" | docker login dogar.darkhelm.org -u "${REGISTRY_USER}" --password-stdin; then
             echo "✓ Successfully logged into registry"
@@ -56,11 +61,6 @@ jobs:
             exit 0
           fi
 
-          # Calculate hash of base Dockerfile for cache key
-          BASE_HASH=$(sha256sum Dockerfile.cicd-base | cut -d' ' -f1 | head -c16)
-          echo "Base Dockerfile hash: ${BASE_HASH}"
-          echo "base_hash=${BASE_HASH}" >> $GITHUB_OUTPUT
-
           # Try to pull existing base image with this hash (with timeout handling)
           echo "Attempting to pull base image with hash: ${BASE_HASH}"
           PULL_SUCCESS=false
@@ -103,6 +103,14 @@ jobs:
           BASE_HASH: ${{ steps.check-base.outputs.base_hash }}
         run: |
           echo "=== Building CICD Base Image ==="
+
+          # Defensive fallback if output propagation failed for any reason.
+          BASE_HASH="${BASE_HASH:-$(sha256sum Dockerfile.cicd-base | cut -d' ' -f1 | head -c16)}"
+          if [ -z "${BASE_HASH}" ]; then
+            echo "❌ BASE_HASH is empty; refusing to tag/push invalid image references"
+            exit 1
+          fi
+
           echo "Base hash: ${BASE_HASH}"
 
           # Enable Docker BuildKit