Request for Vercel AI SDK to emit a `ToolDeferredCallChunk` event for tools executed externally, as `ToolApprovalRequestChunk` is only for tools awaiting approval. This is vital for frontend-heavy applications using Pydantic AI with Vercel AI SDK.
### Description Hi there.👋 ## To emit a `ToolDeferredCallChunk` We currently emit `ToolApprovalRequestChunk` for tools waiting for approval but not for the tools that are going to be executed externally. In a setup that some of the tool executions take place in the frontend, this is vital. A desktop app with Vercel AI sdk/Next/Electron as the frontend and PydanticAI/AWS AgentCore as the backend, for example. Otherwise one has to rely on `ToolInputAvailableChunk` in which the tool call args are still **unvalidated** (or another event that you're aware of?). https://github.com/pydantic/pydantic-ai/blob/2b0aa93a9aea08ddfcdae03605fdb0d5a2486eec/pydantic_ai_slim/pydantic_ai/ui/vercel_ai/_event_stream.py#L122-L137 ### References _No response_