Allow publishers to retain every remote image tag

Fixes bug-bkhzrg4dzz00

Authored-By: Codex (GPT-6) <noreply@openai.com>

action.yaml

@@ -21,6 +21,10 @@ inputs:
     description: Also push a :latest tag
     required: false
     default: 'true'
+  prune:
+    description: Prune old numeric registry tags; false retains every remote tag
+    required: false
+    default: 'true'
   keep:
     description: Numeric tags to retain after prune; older ones are deleted
     required: false
@@ -28,6 +32,16 @@ inputs:
 runs:
   using: composite
   steps:
+    - name: Validate pruning policy
+      shell: bash
+      env:
+        PRUNE: ${{ inputs.prune }}
+      run: |
+        case "$PRUNE" in
+          true|false) ;;
+          *) echo "prune must be true or false" >&2; exit 1 ;;
+        esac
+
     - name: Log in to registry
       uses: docker/login-action@v3
       with:
@@ -54,6 +68,7 @@ runs:
         fi
 
     - name: Prune old tags
+      if: ${{ inputs.prune == 'true' }}
       continue-on-error: true
       shell: bash
       env: