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/src/routes/admin/notifications/+page.server.ts

@@ -0,0 +1,16 @@
+import type { PageServerLoad } from './$types';
+import { backendFetch } from '$lib/server/scraper';
+
+export const load: PageServerLoad = async ({ locals }) => {
+	const userId = locals.user!.id;
+	try {
+		const res = await backendFetch('/api/notifications?user_id=' + userId);
+		const data = await res.json().catch(() => ({ notifications: [] }));
+		return {
+			userId,
+			notifications: (data.notifications ?? []) as Array<{id: string; title: string; message: string; link: string; read: boolean}>
+		};
+	} catch {
+		return { userId, notifications: [] };
+	}
+};