refactor: remove description and rules mock posts

Removed all fake posts for subplebbit description and rules, including dedicated routes, components, and all related logic across the codebase. Board admins can now pin regular posts if they want to provide a description.

src/components/comment-media/comment-media.tsx

@@ -13,8 +13,6 @@ interface MediaProps {
   deleted?: boolean;
   displayHeight?: string;
   displayWidth?: string;
-  isDescription?: boolean;
-  isRules?: boolean;
   isFloatingEmbed?: boolean;
   isOutOfFeed?: boolean;
   isReply?: boolean;
@@ -204,9 +202,7 @@ const Image = ({ commentMediaInfo, displayHeight, displayWidth, isOutOfFeed, par
 const CommentMedia = ({
   commentMediaInfo,
   deleted,
-  isDescription,
   isFloatingEmbed,
-  isRules,
   linkHeight,
   linkWidth,
   parentCid,
@@ -251,7 +247,7 @@ const CommentMedia = ({
     displayWidth = '100%';
     displayHeight = '100%';
   }
-  const isOutOfFeed = isDescription || isRules || isFloatingEmbed || spoiler || false; // virtuoso wrapper unneeded
+  const isOutOfFeed = isFloatingEmbed || spoiler || false; // virtuoso wrapper unneeded
 
   return (
     <span className={styles.content}>