AnyStream

Erased handle useful as a parameter type for helpers and wrapper components that pass a stream through to selector composables without reading values directly. Mirrors the React AnyStream alias.

Widening the generic slots to any is not enough on its own: members computed from T in covariant positions don't collapse to a top type under any. toolCalls: InferToolCalls<any>[] resolves to AssembledToolCall<…, never>[] — the never output slot is narrower than a concrete handle's AssembledToolCall<…, unknown>[], so a fully-typed useStream<typeof agent>() handle would fail to assign and every useToolCalls(stream) call would need an as AnyStream cast. Override toolCalls / values with their widest forms so the erased handle is a true supertype of every concrete UseStreamReturn.