Add local favourites bookmark collection

[AhmedNMahran]

Summary

• Add a localized local-only Favorites collection under the sync collections flow.
• Show ayah bookmarks that are not in any real collection.
• Allow adding/removing ayah bookmarks through the existing collection UI path.

Scope

• QURAN_SYNC-gated collection UI behavior only.
• No Mobile Sync schema/API change.
• No legacy non-sync behavior change.

Notes

• Favourites is app-owned/local-only, not a synced Mobile Sync collection.

Validation

• Sync/non-sync builds were checked locally during implementation.

favorites-1.mov

favorites-2.mov