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/hooks/useMentionClickHandler.ts

@@ -40,7 +40,7 @@ export const useMentionClickHandler = (roomId: string): ReactEventHandler<HTMLEl
 
       navigate(viaServers ? withSearchParam<_RoomSearchParams>(path, { viaServers }) : path);
     },
-    [mx, navigate, navigateRoom, navigateSpace, roomId, space, openProfile]
+    [mx, navigate, navigateRoom, navigateSpace, roomId, space, openProfile],
   );
 
   return handleClick;