refactor(get-images-from-files): to return json array

get-images-from-files/action.yaml

@@ -12,8 +12,8 @@ inputs:
 
 outputs:
   images:
-    description: "Comma-separated list of extracted image references (e.g. docker.io/library/alpine:latest,gcr.io/distroless/static:nonroot@sha256:...)"
-    value: ${{ steps.extract.outputs.images }}
+    description: "JSON array of extracted image reference strings (e.g. [\"docker.io/library/alpine:latest\",\"gcr.io/distroless/static:nonroot@sha256:...\"])"
+    value: ${{ steps.format.outputs.images }}
 
 runs:
   using: "composite"
@@ -45,4 +45,22 @@ runs:
             ' "$f" 2>/dev/null || true
           done | grep -E '/' | sort -u | paste -sd,
         )
-        echo "images=${images:-}" >> "$GITHUB_OUTPUT"
+        echo "images_list=${images:-}" >> "$GITHUB_OUTPUT"
+    - id: format
+      shell: bash
+      run: |
+        set -e
+        list="${{ steps.extract.outputs.images_list }}"
+        json_escape() { printf '%s' "$1" | sed 's/\\/\\\\/g; s/"/\\"/g'; }
+        images="["
+        first=1
+        if [ -n "$list" ]; then
+          IFS=,
+          for img in $list; do
+            [ -z "$img" ] && continue
+            [ "$first" -eq 1 ] && first=0 || images+=","
+            images+="\"$(json_escape "$img")\""
+          done
+        fi
+        images+="]"
+        echo "images=${images}" >> "$GITHUB_OUTPUT"