Studio: API external provider registry + curated catalogs (HF/OpenRouter) and chat UX (#4787)
* fix: external models selectable in chat-only mode
* fix: model selector tabs default to active model kind
* feat(studio): expand provider registry, curated catalogs, and chat UX
- Add Hugging Face, Kimi, Qwen; remove Cohere; reorder registry
- model_list_mode curated for HF/OpenRouter; lightweight /models check
- API returns default models for curated providers; expose model_list_mode
- Frontend: provider logos in model picker, providerType on external models
- Chat providers dialog: curated vs remote flows, motion polish
- Thread: LayoutGroup + composer motion alignment with app easing
* fix(studio): disable Anthropic tool-calling flag and preselect curated defaults
* feat(studio): add external provider logos and ApiProviderLogo helper