fix: remove unused variables from catalog and post views

- catalog.tsx: Remove unused 'coloredFeed' variable assignment in useMemo
- post.tsx: Remove unused 'useState' import

The useMemo in catalog.tsx still executes its side effects (applying filter
colors to the store) without needing to assign the return value.

src/views/catalog/catalog.tsx

@@ -461,8 +461,8 @@ const Catalog = () => {
     };
   }, [clearMatchedFilters, subplebbitAddress]);
 
-  // Apply filter colors to posts when feed changes
-  const coloredFeed = useMemo(() => {
+  // Memoize filter color application to avoid redundant iterations
+  useMemo(() => {
     if (combinedFeed.length > 0 && filterItems.length > 0) {
       // Clear existing matched filters
       clearMatchedFilters();
@@ -482,7 +482,6 @@ const Catalog = () => {
         }
       });
     }
-    return combinedFeed;
   }, [combinedFeed, filterItems, clearMatchedFilters]);
 
   return (

src/views/post/post.tsx

@@ -1,4 +1,4 @@
-import { useEffect, useState } from 'react';
+import { useEffect } from 'react';
 import { useTranslation } from 'react-i18next';
 import { Comment, Role, useComment, useEditedComment, useSubplebbit } from '@plebbit/plebbit-react-hooks';
 import useSubplebbitsStore from '@plebbit/plebbit-react-hooks/dist/stores/subplebbits';