v0.15.0

Minor Changes

• c492c54: Render the new stream_preamble frame: when the operator streams a fast-model preamble ("what I'm about to do") ahead of the answer, show it in the assistant bubble's typing slot (muted + italic) instead of the bare typing dots, then swap in the real answer the moment it starts streaming. A late preamble frame (after the answer began) is ignored. Requires @smooai/smooth-operator ≥ 1.22.15 (adds stream_preamble to the event union so the client forwards it).