Backend: initialize a Django session on token obtain (login) so AuthMiddlewareStack can authenticate WebSocket connections; validate the token serializer and map TokenError -> InvalidToken; call django_logout on logout to destroy the session. Frontend: add a CreateChatModal component (DM/group creation) with user search, selection, validation, API mutation and cache invalidation; wire modal into ChatSidebar and add Czech translations for the new UI strings.
Brunobrno
f19375254f