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/useUserPresence.ts

@@ -54,5 +54,5 @@ export const usePresenceLabel = (): Record<Presence, string> =>
       [Presence.Unavailable]: 'Busy',
       [Presence.Offline]: 'Away',
     }),
-    []
+    [],
   );