show proper error for not found bsky posts

app/lish/[did]/[publication]/[rkey]/PostContent.tsx

···
 import { PublishedPollBlock } from "./Blocks/PublishedPollBlock";
 import { PollData } from "./fetchPollData";
 import { ButtonPrimary } from "components/Buttons";
+import { PostNotAvailable } from "components/Blocks/BlueskyPostBlock/BlueskyEmbed";
 
 export function PostContent({
   blocks,
···
     case PubLeafletBlocksBskyPost.isMain(b.block): {
       let uri = b.block.postRef.uri;
       let post = bskyPostData.find((p) => p.uri === uri);
-      if (!post) return <div>no prefetched post rip</div>;
+      if (!post) return <PostNotAvailable />;
       return (
         <PubBlueskyPostBlock
           post={post}