Eng-council sweep: export hygiene, dead code, helper dedup, declare vega-expression

src/app/stores/DatasetStore.ts

@@ -9,7 +9,7 @@
  * Two layers of action live here:
  *   - Low-level mutators (`add`/`update`/`remove`) are the single place the
  *     `datasets` array changes; the persistence subscriber writes them through to
- *     IndexedDB, and services (RelationshipService, future import) reuse them.
+ *     IndexedDB, and services (e.g. the import flow in services/transfer) reuse them.
  *   - Form orchestration (`save`) validates the form (name required + unique,
  *     data detectable) and turns it into an `add`/`update`, keeping the modal
  *     component thin.
@@ -31,7 +31,7 @@ import { isNameTaken } from '@core/naming';
 import { useSnippetStore } from './SnippetStore';
 
 /** Which pane the Datasets manager is showing (spec §05 → Layout). */
-export type DatasetView = 'list' | 'detail' | 'new' | 'edit';
+type DatasetView = 'list' | 'detail' | 'new' | 'edit';
 
 /** The in-progress create/edit form. `input` is the paste area (inline) or URL field. */
 export interface DatasetForm {