Add reported-issues, Goodreads sync & notifs

Introduce user-reported-issues and Goodreads shelf sync features and wire them into notifications. Adds Prisma migrations and schema changes (ReportedIssue, GoodreadsShelf, GoodreadsBookMapping), API endpoints for reporting (POST /audiobooks/[asin]/report-issue) and admin management (list, resolve/dismiss, replace), and an admin UI section to view/dismiss/replace reported issues. Adds a new notification event (issue_reported) with updates to notification schemas, docs and provider handling, plus a notification-events constants file. Refactors request creation to use createRequestForUser service, adds a Goodreads sync processor/service/hooks/UI modals, a scrape-resilience util, and related tests and minor integration updates.

src/lib/services/notification/INotificationProvider.ts

@@ -3,24 +3,21 @@
  * Documentation: documentation/backend/services/notifications.md
  */
 
-// Event types
-export type NotificationEvent =
-  | 'request_pending_approval'
-  | 'request_approved'
-  | 'request_available'
-  | 'request_error';
+// Re-export event types from central source of truth
+export type { NotificationEvent } from '@/lib/constants/notification-events';
 
 // Backend type — string-based, registry is the runtime source of truth
 export type NotificationBackendType = string;
 
 // Notification payload
 export interface NotificationPayload {
-  event: NotificationEvent;
-  requestId: string;
+  event: import('@/lib/constants/notification-events').NotificationEvent;
+  requestId?: string;
+  issueId?: string;
   title: string;
   author: string;
   userName: string;
-  message?: string; // For error events
+  message?: string; // For error/issue events
   timestamp: Date;
 }