feat(ci): split artifact builds from deployment

.gitea/actions/quickstack-oci/action.yml

@@ -5,6 +5,14 @@ inputs:
     description: Path to the repository deployment manifest.
     required: false
     default: .quickstack/deploy.json
+  mode:
+    description: Execute the complete action, one artifact build slot or only the deployment coordinator.
+    required: false
+    default: all
+  artifact-index:
+    description: Zero-based artifact index used when mode is build.
+    required: false
+    default: "0"
 runs:
   using: composite
   steps:
@@ -12,4 +20,6 @@ runs:
       shell: bash
       env:
         QUICKSTACK_DEPLOY_CONFIG: ${{ inputs.config-path }}
+        QUICKSTACK_ACTION_MODE: ${{ inputs.mode }}
+        QUICKSTACK_ARTIFACT_INDEX: ${{ inputs.artifact-index }}
       run: node "$GITHUB_ACTION_PATH/deploy.mjs"