chore: upgrade i18next 26, prettier 3, fontsource-variable, domhandler 6, lint-staged 17

- i18next 23->26 + react-i18next 15->17
- prettier 2->3, reformat all files
- replace @fontsource/inter with @fontsource-variable/inter 5, update import path
- domhandler 5->6 (aligns with transitive deps)
- lint-staged 16->17

src/app/features/message-search/useMessageSearch.ts

@@ -108,7 +108,7 @@ export const useMessageSearch = (params: MessageSearchParams) => {
       });
       return parseSearchResult(r);
     },
-    [mx, term, order, rooms, senders]
+    [mx, term, order, rooms, senders],
   );
 
   return searchMessages;