Previously `hasThinking = !!cot || reasoningActive || (busy && !hasTools)`
so the moment a tool started streaming (`hasTools` → true) the expander
vanished mid-turn. If the model also produced no `reasoning.delta`
events (reasoning-less models, or reasoning arriving after tools), the
whole turn ran with no Thinking row — then `message.complete`
populated `msg.thinking` from the payload's post-hoc reasoning trace
and the expander suddenly appeared in the transcript AFTER the turn.
Drop the `!hasTools` restriction. The Thinking row now anchors for the
entire `busy` window; tools and thinking coexist as sibling sections
(they already did — the exclusion was a UX mistake). Reasoning-less
models show a dim empty header; streaming models show live content;
tool-interleaved turns keep the anchor visible throughout.
26859e3fcb