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 ## [Unreleased]
 
+## [v0.51.596] — 2026-06-23 — Release VC (throttle reasoning SSE to stop tab freeze)
+
 ### Fixed
 
 - **Reasoning SSE events no longer flood the frontend renderer.** During the reasoning/thinking phase of models like DeepSeek, the server emitted one SSE `reasoning` event per token — tens of thousands per turn — each triggering a full-text scan in the frontend renderer, locking the JS main thread (browser tab freeze). Reasoning SSE events are now throttled to ~10 Hz via a coalescing buffer: delta text is accumulated server-side and flushed in batches, so every reasoning token reaches the browser's live Thinking view while capping SSE events to ~10 Hz. The accumulated reasoning text remains complete for persistence. Thanks @wlknight.