fix(stats): report complete vocabulary totals and new-word history (#202)

src/core/services/immersion-tracker/lexical-rollup-worker.ts

@@ -0,0 +1,15 @@
+import { areLexicalDailyRollupsReady, rebuildLexicalDailyRollups } from './lexical-rollups';
+import { Database } from './sqlite';
+import { applyPragmas } from './storage';
+
+export function executeLexicalRollupBackfillTask(dbPath: string): void {
+  const db = new Database(dbPath);
+  try {
+    applyPragmas(db);
+    if (!areLexicalDailyRollupsReady(db)) {
+      rebuildLexicalDailyRollups(db);
+    }
+  } finally {
+    db.close();
+  }
+}