fix(xtream): retain saved snapshots through browser restore retries

docs/architecture/nx-workspace-boundaries.md

@@ -250,6 +250,18 @@ context panel use, out of that barrel for the same reason, and
 22 KB, used only by the lazy settings page) out of the `@iptvnator/services`
 barrel.
 
+`@iptvnator/services/pwa-xtream-backup-storage` exposes the framework-free browser
+backup persistence implementation without re-exporting it from the eager services
+barrel. The injected backup service wraps it; deferred restore loads it through a
+local dynamic-import module with the data source's storage. Its map keys live in
+a separate pure module so it does not import the Angular storage token at runtime.
+Electron favorites likewise load their
+legacy pending-conversion helper only when a favorites operation needs it.
+Those lazy helpers value-import the pure normalizer through
+`@iptvnator/shared/interfaces/xtream-restore-state`; their remaining contracts
+use type-only imports so a deferred conversion does not load the interfaces
+barrel's Angular/IndexedDB dependencies.
+
 The web app's root shell (`app.component.ts`, `app.config.ts` and the services
 they construct) is on the renderer's initial path, where a barrel costs its
 whole library: esbuild keeps every Angular component module a barrel

docs/architecture/xtream-portal-compatibility.md

@@ -101,6 +101,14 @@ Browser imports convert desktop favorite snapshots into typed collection-cache
 rows so saved titles and artwork remain visible offline. Browser exports include
 the normalized nested favorite snapshots as well as their optional collection
 cache, preserving metadata when the archive returns to Electron.
+Initial browser imports and deferred retries share `PwaXtreamBackupStorage`;
+`PwaXtreamBackupStateService` supplies its injected storage for the importer.
+Both write the lists first and require the nested favorite snapshots to persist
+before consuming pending state. A quota or storage failure keeps the archive
+parked for another attempt, including when the provider returns an empty catalog.
+Legacy browser-only `collectionItems` remain an optional cache; their quota
+failure does not invalidate a restore with no durable nested favorite snapshots.
+The PWA retry loads that storage implementation on demand through a local module.
 
 Both Xtream data-source and portal-activity capabilities require the pending
 favorite conversion bridge; activity reads also require playlist lookup. The