feat: add admin reports API route

- GET /admin/reports with pagination, status filtering, joins, and batch author name lookup
- PATCH /admin/reports/:id/status to review (soft-delete entry) or dismiss
- Register route in lib/api/index.ts and app/api/[[...slugs]]/route.ts

lib/api/index.ts

@@ -11,3 +11,4 @@ export { hardwareStatsRoutes } from "./hardware-stats"
 export { savedGamesRoutes } from "./saved-games"
 export { reportRoutes } from "./reports"
 export { contactRoutes } from "./contact"
+export { adminReportRoutes } from "./admin-reports"