fix(api): normalize empty list responses

lib/api/notifications.ts

@@ -3,7 +3,7 @@ import type { Notification } from "@/lib/types"
 import { httpJson } from "./http"
 
 type Paginated<T> = {
-  items: T[]
+  items: T[] | null
   meta: {
     total: number
     offset: number
@@ -26,7 +26,7 @@ export async function listNotifications(input?: {
   const res = await httpJson<Paginated<Notification>>(`/api/v1/notifications?${searchParams}`, {
     cache: "no-store",
   })
-  return res.items
+  return res.items ?? []
 }
 
 export async function markNotificationAsRead(notificationId: string): Promise<void> {