概述 / Summary

将桌面端聊天面板的动画系统全面迁移到 GSAP 驱动：用精确的高度 tween 替代 CSS max-height hack，消除流式滚动的抖动，为审批卡片添加平滑的进场/退场动画。同时清理了废弃的 minimal 展示模式和 expandThinking 设置。

Migrates the desktop chat transcript's animation to GSAP: replaces CSS max-height hacks with precise height tweens, eliminates streaming scroll jitter, adds smooth enter/exit transitions for approval cards, and removes the obsolete minimal display mode and expandThinking setting.

改动内容 / What changed

1. GSAP 折叠系统 / GSAP collapse system (useGSAPCollapse)

用统一的 useGSAPCollapse hook 替换所有 max-height: 0 → 5000px 的 CSS 过渡。通过 GSAP 精确测量 scrollHeight 并 tween height 属性。使用 useLayoutEffect 在浏览器 paint 之前设置初始折叠状态，消除"闪开"帧。WarmTurnCard 关闭时通过 prevHeight 选项捕获展开高度后再收缩。

Replaces all CSS max-height: 0 → 5000px transitions on collapsible sections (reasoning, tool cards, read-only batches, turn collapse) with a single hook that measures scrollHeight precisely and tweens height via GSAP. Uses useLayoutEffect to set the initial collapsed state before browser paint. WarmTurnCard captures expanded height before DOM swap via prevHeight option.

2. 流式滚动：即时到位 / Streaming scroll: instant, not GSAP tween

旧代码每个 token 都运行 gsap.to(el, { scrollTo, duration: 0.12 })，造成永无止境的 kill/restart 循环。现在流式期间改用 el.scrollTop = el.scrollHeight 直接赋值。onScroll 能区分内容增长（工具调用 output 到达使 scrollHeight 被动变大）和用户主动上滚，避免工具调用展开时误杀自动滚动。

Replaced gsap.to(scrollTo) during streaming with direct scrollTop assignment — the old 120ms tween was perpetually killed/restarted by new tokens. onScroll distinguishes content growth (tool output arriving pushes scrollHeight up) from user-initiated scroll-up by tracking scrollHeight deltas.

3. 入口动画批处理 / Entrance animation batching (useEntranceAnimation)

• 首帧预充值 seen ID 集合，历史条目不执行入口动画
• 新增 resetKey 参数：切换会话时重置 seen + firstRun，避免新会话的 500 条历史全部逐条 fadeIn+slideUp（≈20 秒动画）
• 合并为单个 useEffect（原来是两个，各跑一次 querySelectorAll 扫描整个 DOM 子树）

Pre-seeds seen ID set on first mount so history items never animate. resetKey parameter clears seen + firstRun on session switch, preventing ~20 seconds of cascading entrance animations on 500+ items. Merged into a single useEffect — removed the duplicate querySelectorAll scan.

4. 审批卡片退场动画 / Approval card exit animation

模型同时创建多个文件等待审批时，卡片之前是生硬消失。现在 ApprovalModal 使用 gsap.to(el, { opacity: 0, y: 8, duration: 0.12 }) 退场动画后再调用回答回调。添加 key={approval.id} 修复 React 实例复用 bug——第二张卡继承了第一张卡的 closingRef 导致后续点击被拦截。

Smooth exit animation (opacity + translateY, 120ms) replaces jarring instant removal when model creates multiple files requiring approval. key={approval.id} fixes React instance reuse where the second card inherited a stale closingRef.

5. Markdown 光标优化 / Markdown cursor optimization

injectStreamingCursor 用 deepestLastInlineElement (O(depth)) 替代 TreeWalker (O(nodes))，光标已在正确位置时跳过整个 DOM 写入。

Replaced TreeWalker (O(nodes)) with deepestLastInlineElement (O(depth)). Skips DOM mutation entirely when cursor is already correctly positioned.

6. 删除 minimal 展示模式 / Removed minimal display mode

minimal 模式在代码中与 compact 完全等价。从类型系统、SettingsPanel UI、bridge、types 和三种语言文件中移除。默认值改为 compact。

The minimal mode was identical to compact in code. Removed from type system, SettingsPanel UI, bridge bindings, types, and all 3 locale files. Default switched to compact.

7. 删除 expandThinking 设置 / Removed expandThinking setting

思考过程现在硬编码为"运行中展开、完成折叠"（AssistantMessage 内部逻辑不变）。用户手动展开不会被强制关闭。从 App.tsx、Transcript、SettingsPanel、bridge、types 和语言文件中移除。

Hardcoded: always auto-open while streaming, auto-close on completion. Manual toggle is preserved and never force-closed. Removed from 9 files.

8. JumpBar 性能优化 / JumpBar performance

• markerCache 缓存元素位置，仅在 questions 变化或 .jump-scroll 滚动时重建
• mousemove 不再每次调用 getBoundingClientRect（避免 layout thrashing）
• setHovered 仅在目标问题变化时触发 React 重渲染
• onClick 恢复单击跳转
• barTop 每次调用实时读取 DOM（nav 是 sticky，位置随 transcript 滚动变化）

Position cache eliminates getBoundingClientRect on every mousemove. setHovered only triggers React re-render when the target question changes. onClick restored for single-click jump. Fresh barTop each call for sticky nav.

9. 移除 useScrollManager / Removed useScrollManager

滚动逻辑从独立模块内联回 Transcript。复杂度从 130 行的独立 hook 降为直接 scrollTop = scrollHeight + useLayoutEffect。

Scrolling logic inlined from a separate 130-line module into Transcript. Simpler, fewer cross-module deps.

已知遗留 / Known Caveats

• Go 后端仍序列化 ExpandThinking（settings_app.go:158），前端忽略，无功能影响
• TurnCollapse/ToolCard/ReadOnlyBatch 改为始终渲染 children（GSAP 测量需要），VDOM 树略大，实测 500 条会话无性能影响