perf: eliminate redundant derived state in board and post views

src/views/board/board.tsx

@@ -269,15 +269,7 @@ const Board = () => {
     document.title = boardTitle + ' - plebchan';
   }, [title, shortAddress, subplebbitAddress]);
 
-  // probably not necessary to show the error to the user if the feed loaded successfully
-  const [shouldShowErrorToUser, setShouldShowErrorToUser] = useState(false);
-  useEffect(() => {
-    if (error?.message && feed.length === 0) {
-      setShouldShowErrorToUser(true);
-    } else if (feed.length > 0) {
-      setShouldShowErrorToUser(false);
-    }
-  }, [error, feed]);
+  const shouldShowErrorToUser = error?.message && feed.length === 0;
 
   return (
     <>

src/views/catalog/catalog.tsx

@@ -462,7 +462,7 @@ const Catalog = () => {
   }, [clearMatchedFilters, subplebbitAddress]);
 
   // Apply filter colors to posts when feed changes
-  useEffect(() => {
+  const coloredFeed = useMemo(() => {
     if (combinedFeed.length > 0 && filterItems.length > 0) {
       // Clear existing matched filters
       clearMatchedFilters();
@@ -482,6 +482,7 @@ const Catalog = () => {
         }
       });
     }
+    return combinedFeed;
   }, [combinedFeed, filterItems, clearMatchedFilters]);
 
   return (

src/views/post/post.tsx

@@ -85,14 +85,7 @@ const PostPage = () => {
   }, [title, shortAddress, subplebbitAddress, post?.title, post?.content, isInAllView, t]);
 
   // probably not necessary to show the error to the user if the post loaded successfully
-  const [shouldShowErrorToUser, setShouldShowErrorToUser] = useState(false);
-  useEffect(() => {
-    if (post?.error && ((post?.replyCount > 0 && post?.replies?.length === 0) || (post?.state === 'failed' && post?.error))) {
-      setShouldShowErrorToUser(true);
-    } else if (post?.replyCount > 0 && post?.replies?.length > 0) {
-      setShouldShowErrorToUser(false);
-    }
-  }, [post]);
+  const shouldShowErrorToUser = post?.error && ((post?.replyCount > 0 && post?.replies?.length === 0) || (post?.state === 'failed' && post?.error));
 
   return (
     <div className={styles.content}>