Flush throttled reasoning before state-transition events (MessageStart/
Complete/Done/ToolStart) so a reasoning delta arriving just before a
transition is not dropped. Also compare reasoningText in sameMessages so
a reasoning-only restore actually re-merges.
- ChatStreamingController.flushPendingReasoning() forces a synchronous flush
- handleWsEvent calls it for the transition events
- sameMessages now includes reasoningText in its equality check
- tests: ChatStreamingControllerTest (flush + no-resurrect), reasoning survives
MessageDone after an unflushed delta
Co-authored-by: M57 <hy4ri@users.noreply.github.com>
