Function sse_response_with_tool_calls 

pub fn sse_response_with_tool_calls(stream: ChatStream, model: &str) -> Response

Convert a ChatStream into an SSE response that streams prose as content deltas and completed <tool_call> blocks as tool_calls deltas.

Unlike sse_single_response, which buffers the whole completion, this forwards tokens incrementally. Used when a tools-bearing request targets a provider that supports streaming.