feat(types): sync published types with source StoryAPI

src/types-drift-check.ts

@@ -0,0 +1,15 @@
+/**
+ * Compile-time check: the hand-written types/index.d.ts must stay in sync
+ * with the source StoryAPI interface.  If this file fails to compile,
+ * the published types have drifted from the implementation.
+ *
+ * Run: npx tsc --noEmit
+ */
+import type { StoryAPI as SourceAPI } from './story-api';
+import type { StoryAPI as PublishedAPI } from '../types/index';
+
+// Both directions — if either fails, the types have drifted.
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+const _sourceToPublished: PublishedAPI = {} as SourceAPI;
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+const _publishedToSource: SourceAPI = {} as PublishedAPI;