fix(api): normalize empty list responses

lib/api/posts.ts

@@ -4,7 +4,7 @@ import type { Post } from "@/lib/types"
 import { httpJson } from "./http"
 
 type Paginated<T> = {
-  items: T[]
+  items: T[] | null
   meta: {
     total: number
     offset: number
@@ -40,7 +40,7 @@ export async function listPosts(options?: ListOptions): Promise<Post[]> {
   const res = await httpJson<Paginated<Post>>(withOffsetLimit("/api/v1/posts", options), {
     cache: "no-store",
   })
-  return res.items
+  return res.items ?? []
 }
 
 export async function getPostById(postId: string): Promise<Post | undefined> {
@@ -80,7 +80,7 @@ export async function listPostsByAuthor(userId: string, options?: ListOptions):
       cache: "no-store",
     },
   )
-  return res.items
+  return res.items ?? []
 }
 
 export async function togglePostLike(postId: string, currentlyLiked: boolean): Promise<void> {