* native-chat: render one indicator row for the live desktop turn
The turn-timing row and the spinner+activity line were two rows saying
"Working" at once. A settled turn keeps its own row; the live turn now has
only the spinner row, labelled provider activity -> Thinking -> Working for N
through the shared resolver. Reasoning is the turn's content, so it no longer
becomes the activity label, and "Thinking" now means the turn is reasoning
right now rather than that it has produced no output yet.
* mobile: give the live turn row a spinner and the shared indicator label
Mobile's per-turn row is already the only live indicator on the structured
lane, but it pulsed a bare word and never showed what the provider said it was
doing. It now renders a spinner beside the same resolved label desktop uses,
and reads reasoning from the journal instead of inferring it from missing
output. The bridge lane's four prompt/interrupt write seams move to one module
so the controller stays under its line cap.
* codex: mark streamed reasoning as reasoning too, and pin the provider markers
The settled reasoning item carried the marker but the streaming one did not,
so a live Codex turn - the only time the indicator is on screen - never read
as reasoning. Both paths now stamp it; a plan document keeps its own
presentation and must never read as reasoning.
* fix(native-chat): tighten live turn reasoning state
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Co-authored-by: Merge Sim <sim@local>
