fix: BYOK

[kah-seng]

Key changes:

• Select models by ID instead of slug so users can have multiple API keys for the same slug
• Add loading spinner for save/edit actions

[Copilot]

Pull request overview

This PR updates BYOK (custom model) handling so model selection can be disambiguated by a unique custom model ID (instead of slug), and adds a saving/loading UX to the API key settings editor.

Changes:

• Add id + custom_model_id to the chat v2 API (proto + generated clients) and thread customModelId through the webapp stream request builder.
• Update model picker wiring to support selecting custom models by ID (while still displaying slug).
• Add an isSaving state to the BYOK settings UI to disable inputs and show a spinner during save/edit.

Reviewed changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
webapp/_webapp/src/views/settings/sections/api-key-settings.tsx	Adds isSaving state and disables inputs/buttons + spinner during save/edit.
webapp/_webapp/src/views/chat/footer/toolbar/selection.tsx	Extends SelectionItem to optionally carry id/isCustom.
webapp/_webapp/src/views/chat/footer/toolbar/model-selection.tsx	Passes custom model id/isCustom into selection items and selects custom models by ID.
webapp/_webapp/src/utils/stream-request-builder.ts	Adds customModelId into the stream request payload.
webapp/_webapp/src/stores/setting-store.ts	Initializes default settings to include customModels: [].
webapp/_webapp/src/stores/conversation/conversation-ui-store.ts	Persists lastUsedCustomModelId in UI state.
webapp/_webapp/src/hooks/useSendMessageStream.ts	Threads lastUsedCustomModelId into stream requests.
webapp/_webapp/src/hooks/useLanguageModels.ts	Maps SupportedModel.id into UI models and prefers selecting custom models by ID.
proto/chat/v2/chat.proto	Adds SupportedModel.id and CreateConversationMessageStreamRequest.custom_model_id.
pkg/gen/api/chat/v2/chat.pb.go	Regenerates Go protobuf types for the new fields.
webapp/_webapp/src/pkg/gen/apiclient/chat/v2/chat_pb.ts	Regenerates TS protobuf types for the new fields.
internal/api/chat/list_supported_models_v2.go	Populates SupportedModel.id for custom models.
internal/api/chat/create_conversation_message_stream_v2.go	Resolves custom models by custom_model_id instead of slug.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.