fix(gui): address review — stale smoke case, tooltip trigger overlap, collapse contract docs

- The real-browser collapse smoke tracked the old chrome: visible HARNESS
  text (the wordmark svg is aria-hidden now), an 'Expand sidebar' label
  (renamed 'Open sidebar'), a 300px settle (default is 280), and an
  immediate focus assert (rail search defers focus past the slide). The
  case now tracks the brand span, polls the deferred focus, and uses the
  current labels and width.
- Tooltip treated hover and focus as one trigger: leaving with the mouse
  dropped the bubble of a still-focused anchor (and vice versa). The two
  triggers are tracked independently; the bubble hides only after both
  clear. Spec pins both orders.
- The ui-sidebar README and the bilingual collapse note still described
  the retired geometry morph; both now state the slide + crossfade
  contract, the fixed-width (never-conceding) sidebar, and the rail's
  whale-mark/tooltip chrome.

.agents/notes/implemented/bug-fix/2026-07-22-collapsed-sidebar-control-rail.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write
-2026-07-22-collapsed-sidebar-control-rail.md: e959eef37a9e9c0fea79b82ff970daddd9257609
-2026-07-22-collapsed-sidebar-control-rail.zh.md: 7f6d6529a8aa4a655a1d3292e7f41bfb822f05a3
+2026-07-22-collapsed-sidebar-control-rail.md: 940fcabf126941cc0e411b01c337e45831e442aa
+2026-07-22-collapsed-sidebar-control-rail.zh.md: 70ace36fafcb28aa714000262e31c8555d394854

.agents/notes/implemented/bug-fix/2026-07-22-collapsed-sidebar-control-rail.md

@@ -10,11 +10,11 @@ The sidebar close action persisted a zero width preference, and the layout mappe
 
 ## Decision
 
-The layout maps a closed sidebar (persisted width `0`) to the fixed `SIDEBAR_COLLAPSED` width of 56px: a 24px icon column between the sidebar's 16px horizontal paddings. The compact rail participates in the concession solver and retains its right border, while the stored expanded width remains untouched.
+The layout maps a closed sidebar (persisted width `0`) to the fixed `SIDEBAR_COLLAPSED` width of 56px: a 24px icon column between the sidebar's 16px horizontal paddings. The sidebar track is fixed-width in the solver — open or collapsed it never concedes to viewport pressure (only details shrinks, then auto-closes) — and the rail retains its right border while the stored expanded width remains untouched.
 
 `AppFrame` marks the sidebar collapsed from the persisted width preference rather than from the resolved track width, removes the resize handle while collapsed, and passes `collapsed` to the sidebar slot as owner props from the render site. Collapse and expand animate: the frame transitions `grid-template-columns` (and the remaining handle its `left`) on the deepsuite sider curve — `--ds-ease-in-out` over `--ds-transition-duration-slow`, both supplied by ui-theme's base sheet; transitions pause during drags and under `prefers-reduced-motion`.
 
-`SidebarRoot` reads the owner `collapsed` prop and morphs in place rather than swapping renders: the four control rows persist into the rail — expand toggle, new session, new workspace, search, in the same top-down order as their expanded rows — animating their geometry (heights, paddings, margins, capsule borders) on the same curve, each aligned with its expanded counterpart's behavior (the search icon expands the sidebar and focuses the search box). Wide-only content (brand, labels, input, session tree) cross-fades out over 200ms, stays mounted while the collapse animates, and unmounts once the 300ms settle passes — dropping the sessions subscription and leaving the rendered and accessibility trees. The search query lives with the root and survives the round trip.
+`SidebarRoot` reads the owner `collapsed` prop and transitions as a slide + crossfade: the expanded content freezes at its width (inline style) and fades out in place over 150ms while the sliding grid column clips it — nothing reflows mid-slide. At settle the wide-only content (brand, labels, input, session tree) unmounts — dropping the sessions subscription and leaving the rendered and accessibility trees — and the control rows snap to the rail (open toggle, new session, new workspace, search, the same top-down order as their expanded rows) fading in as the slide ends. Each rail control keeps its expanded counterpart's behavior (the search icon expands the sidebar and focuses the search box after the slide), carries a tooltip, and the toggle rests as the whale mark with the panel icon on hover. The search query lives with the root and survives the round trip.
 
 ## Alternatives considered
 

.agents/notes/implemented/bug-fix/2026-07-22-collapsed-sidebar-control-rail.zh.md

@@ -10,11 +10,11 @@ Status: implemented
 
 ## 决策
 
-布局将关闭的侧边栏（持久化宽度为 `0`）映射为固定的 `SIDEBAR_COLLAPSED` 宽度 56px：在侧边栏两侧各 16px 的水平内边距之间放置一列 24px 的图标控件。紧凑控制栏参与空间收缩求解，并保留右侧边框；已存储的展开宽度保持不变。
+布局将关闭的侧边栏（持久化宽度为 `0`）映射为固定的 `SIDEBAR_COLLAPSED` 宽度 56px：在侧边栏两侧各 16px 的水平内边距之间放置一列 24px 的图标控件。侧边栏轨道在求解器中是定宽的——无论展开还是折叠都不向视口压力让步（只有 details 会收缩、继而自动关闭）；控制栏保留右侧边框，已存储的展开宽度保持不变。
 
 `AppFrame` 根据持久化的宽度偏好标记侧边栏是否折叠，而不是根据求解后的轨道宽度来判断；折叠时移除尺寸调整手柄，并在渲染点把 `collapsed` 作为 owner props 传给侧边栏插槽。折叠与展开带动画：frame 对 `grid-template-columns`（以及余下手柄的 `left`）应用 deepsuite 侧栏曲线过渡——`--ds-ease-in-out` 配 `--ds-transition-duration-slow`，两个变量由 ui-theme 的 base 表提供；拖拽期间和 `prefers-reduced-motion` 下过渡暂停。
 
-`SidebarRoot` 读取 owner 的 `collapsed` 属性，原地 morph 而非切换渲染：四个控件行持续存在并演变为控制栏——展开开关、新建会话、新建工作区、搜索，自上而下与展开态各行顺序一致——几何（行高、内边距、外边距、胶囊边框）走同一条曲线动画，行为与展开态对应控件对齐（搜索图标会展开侧边栏并聚焦搜索框）。宽态专属内容（品牌标识、文字标签、输入框、会话树）以 200ms 交叉淡出，折叠动画期间保持挂载，300ms settle 后卸载——随之退订会话列表并离开渲染树与可访问性树。搜索关键词由根组件持有，折叠往返后保留。
+`SidebarRoot` 读取 owner 的 `collapsed` 属性，过渡是滑动 + 交叉淡变：展开内容以内联样式冻结在原宽度、150ms 原地淡出，滑动中的网格列裁切它——滑动途中不发生任何重排。settle 时宽态专属内容（品牌标识、文字标签、输入框、会话树）卸载——随之退订会话列表并离开渲染树与可访问性树——控件行落位到控制栏（打开开关、新建会话、新建工作区、搜索，自上而下与展开态各行顺序一致），随滑动结束淡入。每个控制栏控件保持与展开态对应控件一致的行为（搜索图标展开侧边栏并在滑动结束后聚焦搜索框）并带 tooltip；开关静止时显示鲸鱼标，悬停切换为面板图标。搜索关键词由根组件持有，折叠往返后保留。
 
 ## 曾考虑的替代方案