fix(idb-cleanup): swallow TransactionInactiveError in idempotent IDB cursor loops (#3335)

Sentry WORLDMONITOR-NX: iOS Safari kills in-flight IDB transactions when
the tab backgrounds. Our idle detector fires `[App] User idle - pausing
animations to save resources` right before the browser suspends — any
`cursor.delete()` / `cursor.continue()` mid-iteration then throws
TransactionInactiveError synchronously inside onsuccess.

Both affected sites are idempotent cleanup (`cleanOldSnapshots`,
`deleteFromIndexedDbByPrefix`); swallowing the throw lets the next run
resume from where we left off. `main.ts` beforeSend keeps TransactionInactiveError
surfaced for first-party stacks (storage.ts, persistent-cache.ts, vector-db.ts),
so this is the correct layer to handle the background-kill case.

src/services/persistent-cache.ts

@@ -82,9 +82,13 @@ async function deleteFromIndexedDbByPrefix(prefix: string): Promise<void> {
     request.onsuccess = () => {
       const cursor = request.result;
       if (!cursor) return;
-
-      store.delete(cursor.primaryKey);
-      cursor.continue();
+      // iOS Safari kills in-flight IDB transactions when the tab backgrounds;
+      // prefix-invalidation is idempotent so swallow TransactionInactiveError
+      // and let the next invalidation call resume.
+      try {
+        store.delete(cursor.primaryKey);
+        cursor.continue();
+      } catch { /* tx died mid-iteration */ }
     };
     request.onerror = () => reject(request.error);
   });

src/services/storage.ts

@@ -214,7 +214,10 @@ export async function cleanOldSnapshots(): Promise<void> {
       const request = store.index('by_time').openCursor(IDBKeyRange.upperBound(cutoff));
       request.onsuccess = () => {
         const cursor = request.result;
-        if (cursor) { cursor.delete(); cursor.continue(); }
+        if (!cursor) return;
+        // iOS Safari kills in-flight IDB transactions when the tab backgrounds;
+        // cleanup is idempotent so swallow TransactionInactiveError and resume next run.
+        try { cursor.delete(); cursor.continue(); } catch { /* tx died mid-cleanup */ }
       };
       void tx;
     },