v2.6.50: notifications overhaul, fix blank page, fix chapter review loading

- svelte.config.js: paths.relative=false so CSS uses absolute /_app/ paths (fixes blank home page after redirect)
- ai-jobs: fix openReview() mutating stale alias r instead of $state review — was causing 'Loading results...' to never resolve for chapter-names/image-gen/description
- notifications bell: redesign with All/Unread tabs, per-item dismiss (×), mark-all-read, clear-all, 'View all' footer link
- /admin/notifications: new dedicated full-page notifications view
- api/notifications proxy: add PATCH (mark-all-read) and DELETE (clear-all, dismiss) handlers
- runner: add CreateNotification calls on success/failure in runScrapeTask, runAudioTask, runTranslationTask
- storage/import.go: real PDF (dslipak/pdf) and EPUB (archive/zip + x/net/html) parsing replacing stubs
- translation admin page: stream jobs Promise instead of blocking navigation
- store.go: DeleteNotification, ClearAllNotifications, MarkAllNotificationsRead methods
- handlers_notifications.go + server.go: PATCH /api/notifications, DELETE /api/notifications, DELETE /api/notifications/{id}

ui/svelte.config.js

@@ -3,7 +3,10 @@ import adapter from '@sveltejs/adapter-node';
 /** @type {import('@sveltejs/kit').Config} */
 const config = {
 	kit: {
-		adapter: adapter()
+		adapter: adapter(),
+		paths: {
+			relative: false
+		}
 	}
 };