Add Stationery and Stationery Dark themes with notebook chrome.

Manila folders, ruled chat, post-it nav, and folder tabs; dark variant uses Catppuccin Mocha colors with muted stickies and soft glows.

src/app/features/room/message/Reactions.tsx

@@ -55,6 +55,7 @@ export const Reactions = as<'div', ReactionsProps>(
         className={classNames(css.ReactionsContainer, className)}
         gap="200"
         wrap="Wrap"
+        data-reactions=""
         {...props}
         ref={ref}
       >