fix(settings): withhold the Xtream catalog at relock time, keep exact M3U titles in backups, roll back a failed relock-timeout save

- A relock now fails closed immediately: the selected detail is stepped
  off against the lock store, the catalog lists and stored search results
  are emptied, and the filtered reloads publish only while the captured
  lock version is still current.
- Backups carry M3U lock titles verbatim (exact dedup), since the locks
  match group titles exactly.
- A relock-timeout write that fails reverts the in-memory value and shows
  the settings save-failure snackbar.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

libs/shared/interfaces/src/lib/parental-lock.util.spec.ts

@@ -1,5 +1,6 @@
 import {
     isParentalLockPlaylistLocksEmpty,
+    normalizeParentalLockGroupTitles,
     isWellFormedParentalLockStore,
     lockedStalkerCategoryIds,
     lockedXtreamCategoryIds,
@@ -147,3 +148,11 @@ describe('isWellFormedParentalLockStore', () => {
         expect(isWellFormedParentalLockStore(value)).toBe(false);
     });
 });
+
+describe('normalizeParentalLockGroupTitles', () => {
+    it('deduplicates exactly, keeping surrounding whitespace', () => {
+        expect(
+            normalizeParentalLockGroupTitles([' Adult ', ' Adult ', 'Adult', 7])
+        ).toEqual([' Adult ', 'Adult']);
+    });
+});