Add dataset library, extract-to-dataset, and render-time reference resolution

src/app/infrastructure/dataset-store.ts

@@ -0,0 +1,28 @@
+/**
+ * Dataset persistence adapter (docs/architecture/02, spec §09E).
+ *
+ * The typed seam between the dataset store and IndexedDB's high-capacity
+ * `datasets` object store (separate from snippets so large payloads live in a
+ * tier suited to them). Exposes plain async functions returning domain `Dataset`
+ * objects and migrates every record on read.
+ */
+
+import { CURRENT_DATASET_VERSION, type Dataset } from '@core/dataset';
+import { DATASETS_STORE, del, getAll, put } from './db';
+import { migrateDataset } from './dataset-migrations';
+
+/** Load every dataset, upgrading each record to the current shape. */
+export async function loadDatasets(): Promise<Dataset[]> {
+  const records = await getAll<unknown>(DATASETS_STORE);
+  return records.map(migrateDataset);
+}
+
+/** Persist a dataset at the current schema version. Propagates failures. */
+export async function saveDataset(dataset: Dataset): Promise<void> {
+  await put(DATASETS_STORE, { ...dataset, version: CURRENT_DATASET_VERSION });
+}
+
+/** Permanently remove a dataset by id. */
+export async function deleteDataset(id: number): Promise<void> {
+  await del(DATASETS_STORE, id);
+}