fix: prevent full width switch from stealing menu focus

.agents/notes/implemented/bug-fix/2026-10-20-session-menu-switch-focus.md

@@ -0,0 +1,51 @@
+# Session menu switch focus
+
+Status: implemented
+Translation: current
+
+[中文](2026-10-20-session-menu-switch-focus.zh.md)
+
+PR: [#1741](https://github.com/LodyAI/Lody/pull/1741)
+
+## Abstract
+
+Opening the session actions menu with the pointer highlighted Full width while
+the pointer remained on the trigger. Its nested switch was tabbable, so the
+menu's initial focus chose it and highlighted its containing row. The switch
+now stays outside the tab order, leaving keyboard navigation with the menu row.
+The switch remains directly clickable, and keyboard opening still focuses an
+action; opening alone does not change the preference.
+
+## Decision and evidence
+
+This corrects the focus behavior of the trailing switch introduced by
+[conversation full-width mode](../feature/2026-09-28-conversation-wide-mode.md).
+Base UI 1.7's menu popup focuses its first tabbable descendant on pointer open;
+menu rows initially have `tabIndex=-1`, but the nested switch did not. Setting
+`tabIndex=-1` on that switch allows the popup surface to receive pointer-open
+focus, while Base UI's existing keyboard navigation still reaches the row.
+There is no shared menu autofocus override or hidden highlight styling.
+
+The containing row keeps its keyboard activation and `closeOnClick=false`;
+the switch retains its own click handler and propagation stop. This preserves
+both direct pointer activation and the visible switch design without giving
+the nested control a second keyboard stop.
+
+## Verification
+
+The owning session-header and full-width suites pass all 15 tests. Regression
+coverage checks pointer opening, arrow navigation, keyboard opening, dismissal,
+and preference changes through both row activation and direct switch clicks.
+A real SessionHeaderMenu Storybook browser run also verifies pointer opening,
+hover, keyboard opening, row activation, direct switch clicks, and Escape dismissal.
+The full `pnpm check` passes, including workspace type checking, typed and Effect
+lint, all configured workspace tests, i18n validation, and boundary guards.
+`pnpm format` also passes.
+The documentation check still reports six existing missing local Kimi/Pi
+submodule links in the subagent-events note; this change adds no broken links.
+
+The synthetic Storybook fixture omits optional Share and owner-transfer callbacks;
+those production entries retain their existing conditions. The pointer remains
+on the trigger when this screenshot is captured.
+
+![Pointer-opened menu](../../assets/session-menu-switch-focus/after.png)

.agents/notes/implemented/bug-fix/2026-10-20-session-menu-switch-focus.zh.md

@@ -0,0 +1,43 @@
+# 会话菜单开关焦点
+
+Status: implemented
+Translation: current
+
+[English](2026-10-20-session-menu-switch-focus.md)
+
+PR: [#1741](https://github.com/LodyAI/Lody/pull/1741)
+
+## 摘要
+
+用鼠标打开会话操作菜单时，指针还停留在触发按钮上，“全宽显示”就出现了高亮。
+原因是行内开关可以接收 Tab 焦点，菜单的初始焦点选择了它，并使所在行高亮。
+现在将开关移出 Tab 顺序，键盘导航由菜单行统一承接。
+开关仍然可以直接点击，键盘打开时仍会聚焦操作项；仅打开菜单不会改变偏好。
+
+## 决定与证据
+
+本次修正[会话全宽模式](../feature/2026-09-28-conversation-wide-mode.md)
+引入的行尾开关的焦点行为。Base UI 1.7 的菜单弹层在鼠标打开时会聚焦第一个
+可以通过 Tab 到达的后代；菜单行最初为 `tabIndex=-1`，但嵌套开关没有该限制。
+为开关设置 `tabIndex=-1` 后，鼠标打开时焦点留在菜单表面，原有键盘导航仍会
+进入菜单行。无需覆盖共享菜单的自动聚焦逻辑，也没有用样式隐藏高亮。
+
+外层菜单行保留键盘激活与 `closeOnClick=false`；开关保留自己的点击处理与
+阻止冒泡。因此用户仍可直接点击开关，视觉设计保持不变，并且不会多出第二个
+键盘停靠点。
+
+## 验证
+
+所属的会话菜单与全宽模式测试共 15 项全部通过。回归测试覆盖鼠标打开、方向键导航、
+键盘打开、关闭菜单，以及通过菜单行和直接点击开关改变偏好。
+浏览器中也通过真实 SessionHeaderMenu Storybook 组件验证了鼠标打开、悬停、键盘打开、
+菜单行激活、直接点击开关，以及 Escape 关闭。
+完整的 `pnpm check` 通过，包括工作区类型检查、类型感知与 Effect lint、全部配置的
+工作区测试、国际化验证和边界检查；`pnpm format` 也通过。
+文档检查仍报告 subagent-events 笔记中原有的六个本地 Kimi/Pi 子模块缺失链接；
+本次修改没有新增失效链接。
+
+截图来自合成的 Storybook 示例，未配置可选的分享和所有者转移回调；生产页面
+仍保留这些入口原有的显示条件。截图时指针停留在触发按钮上。
+
+![Pointer-opened menu](../../assets/session-menu-switch-focus/after.png)

packages/components/src/components/sessions/README.md

@@ -14,6 +14,11 @@ The navigation-sidebar, terminal-dock and right-panel toggles reuse
 rotated -90 degrees and the right-panel glyph 180 degrees so the filled strip
 marks the panel's edge; their buttons and toggle behavior stay shared.
 
+The header's Full width row owns keyboard navigation; its trailing switch stays
+outside the tab order. Pointer opening focuses the menu surface without
+highlighting an action, while keyboard opening and arrow navigation focus rows.
+Both the row and the switch toggle the preference without dismissing the menu.
+
 `ask-user-question-card.tsx` owns interactive and read-only question presentation,
 including independent optional notes and secret masking. Its dedicated
 `AskUserQuestionCard` stories cover editing, replay, multiple questions and legacy

packages/components/src/components/sessions/session-chat-interface.tsx

@@ -1677,6 +1677,9 @@ export function SessionHeaderMenu({
             icon={MoveHorizontal}
             endContent={
               <Switch
+                // The menu row owns keyboard focus. A tabbable nested switch
+                // otherwise receives initial focus even when opened by mouse.
+                tabIndex={-1}
                 checked={conversationWide}
                 onCheckedChange={(checked) => setConversationWide(checked === true)}
                 onClick={(event) => event.stopPropagation()}

packages/components/tests/session-header-menu.test.tsx

@@ -6,7 +6,7 @@ import { createStore, Provider } from 'jotai';
 import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
 import type { SessionId, SessionMeta } from '@lody/shared';
 
-import { experimentalFeaturesEnabledAtom } from '../src/atoms/settings';
+import { conversationWideModeAtom, experimentalFeaturesEnabledAtom } from '../src/atoms/settings';
 import { SessionHeaderMenu } from '../src/components/sessions/session-chat-interface';
 import { Tooltip } from '@lody/ui/tooltip';
 
@@ -75,6 +75,7 @@ describe('SessionHeaderMenu', () => {
         new TestPointerEvent('mousedown', {
           bubbles: true,
           button: 0,
+          detail: 1,
           pointerType: 'mouse',
         })
       );
@@ -121,6 +122,66 @@ describe('SessionHeaderMenu', () => {
     expect(container?.querySelector('[data-testid="fork-result"]')?.textContent).toBe('none');
   }
 
+  it('leaves pointer-opened actions unhighlighted and toggles full width only on activation', async () => {
+    const store = createStore();
+    store.set(conversationWideModeAtom, false);
+    await act(async () => {
+      root?.render(
+        <Provider store={store}>
+          <ForkMenuHarness />
+        </Provider>
+      );
+    });
+    await openMenu();
+
+    const menu = document.querySelector('[role="menu"]');
+    const fullWidth = menuItem('Full width');
+    const toggle = fullWidth.querySelector<HTMLButtonElement>('[role="switch"]')!;
+    expect(document.activeElement).toBe(menu);
+    expect(menu?.querySelector('[data-highlighted]')).toBeNull();
+    expect(store.get(conversationWideModeAtom)).toBe(false);
+
+    await act(async () => {
+      menu?.dispatchEvent(new KeyboardEvent('keydown', { key: 'ArrowDown', bubbles: true }));
+      await vi.advanceTimersByTimeAsync(40);
+    });
+    expect(document.activeElement).toBe(fullWidth);
+    expect(fullWidth.hasAttribute('data-highlighted')).toBe(true);
+
+    await act(async () => {
+      fullWidth.dispatchEvent(new KeyboardEvent('keydown', { key: 'Enter', bubbles: true }));
+    });
+    expect(store.get(conversationWideModeAtom)).toBe(true);
+    expect(document.querySelector('[role="menu"]')).toBe(menu);
+
+    await act(async () => toggle.click());
+    expect(store.get(conversationWideModeAtom)).toBe(false);
+    expect(document.querySelector('[role="menu"]')).toBe(menu);
+  });
+
+  it('focuses the first action when the menu is opened with the keyboard', async () => {
+    await act(async () => root?.render(<ForkMenuHarness />));
+    const trigger = container!.querySelector<HTMLButtonElement>(
+      'button[aria-label="More actions"]'
+    )!;
+    await act(async () => {
+      trigger.focus();
+      trigger.dispatchEvent(new KeyboardEvent('keydown', { key: 'ArrowDown', bubbles: true }));
+      await vi.advanceTimersByTimeAsync(40);
+    });
+    const fullWidth = menuItem('Full width');
+    expect(document.activeElement).toBe(fullWidth);
+    expect(fullWidth.hasAttribute('data-highlighted')).toBe(true);
+
+    await act(async () => {
+      fullWidth.dispatchEvent(new KeyboardEvent('keydown', { key: 'Escape', bubbles: true }));
+    });
+    await act(async () => {
+      await vi.advanceTimersByTimeAsync(40);
+    });
+    expect(document.querySelector('[role="menu"]')).toBeNull();
+  });
+
   it('opens the submenu and forks to a new tab', async () => {
     await act(async () => root?.render(<ForkMenuHarness />));
     await openForkMenu();