fix(ui): reduce UI flicker — throttle 60→100ms + startTransition + batch STREAM_TEXT

[aspnmy]

What

Three changes to reduce UI flicker, each with tests:

B1 — throttle 60→100ms

• useGeminiStream.ts: STREAM_UPDATE_THROTTLE_MS 60 → 100
• useGeminiStream.test.tsx: 7 test timers updated (60→100ms)

A2 — compactMode toggle via startTransition

• App.tsx: wrap setCompactMode in startTransition

C1 — batch STREAM_TEXT per chunk

• agent-core.ts: accumulate text parts, emit once per chunk

Why

• Fixes qwencode在紧缩模式下，ctrl+O开启后，执行任务会频繁闪屏。 #4561: Ctrl+O compact mode flicker on Windows
• Fixes 终端界面无限滚动/刷新循环 #3838: Infinite refresh loop with source output
• Fixes [Bug] 模型调用并行子Agent时, TUI出现频繁闪烁 #2928: Parallel sub-agent flicker

Files

4 files changed, 40 insertions(+), 19 deletions(-)

• Source: useGeminiStream.ts, App.tsx, agent-core.ts
• Tests: useGeminiStream.test.tsx (7 timer updates)
• No loopDetectionService changes — clean version of fix(ui): reduce UI flicker — throttle + startTransition + batch STREAM_TEXT + debounce refresh + resize settle #5396
• Based on latest main v0.19.5, zero merge conflicts

[qwen-code-ci-bot]

Hi @aspnmy, thanks for the PR!

The code changes look focused and the direction is solid — UI flicker is a well-known pain point, and the three changes (throttle bump, startTransition, batched emits) are all reasonable approaches.

However, the PR body is missing several required sections from the PR template:

• Reviewer Test Plan — How to verify, Before/After evidence, and Tested-on OS. This is especially important for UI flicker fixes since reviewers need to know what to look for and on which platforms the fix was validated.
• Risk & Scope — Main risk or tradeoff, what's out of scope, any breaking changes.
• Linked Issues — Please use Closes #N / Fixes #N in a dedicated section so issues auto-close on merge.
• 中文说明 — The template includes a collapsible Chinese translation section.

Could you update the PR description to fill in these sections? Once that's done, the review can proceed.

中文说明

你好 @aspnmy，感谢你的 PR！

代码改动很聚焦，方向也是对的——UI 闪烁是一个已知的痛点，三个改动（节流值调整、startTransition、批量发送）都是合理的方案。

但 PR 描述缺少 PR 模板 中的几个必填部分：

• Reviewer Test Plan — 验证方式、修复前后对比、测试过的操作系统。对于 UI 闪烁修复尤其重要，审查者需要知道该观察什么、在哪些平台上验证过。
• Risk & Scope — 主要风险或权衡、不在范围内的内容、是否有破坏性变更。
• Linked Issues — 请在专门的部分使用 Closes #N / Fixes #N，以便合并时自动关闭 issue。
• 中文说明 — 模板包含一个可折叠的中文翻译部分。

请补充这些部分，之后可以继续审查流程。

— Qwen Code · qwen3.7-max