fix(web-shell): localize remaining hardcoded UI strings (#5189)

Route the last few hardcoded English strings in web-shell through the
existing useI18n()/t() layer and add matching en / zh-CN keys:

- close-button tooltips across 9 dialogs
- the history-search label, placeholder and key hint in the editor
- icon-button aria-labels (toast dismiss, thinking toggle, sub-agent
  stream toggle), which also improves screen-reader support

No new i18n infrastructure; follows the existing pattern used by the
same components.

Co-authored-by: qingyu <qingyu@taobao.com>
Co-authored-by: 易良 <1204183885@qq.com>

packages/web-shell/client/components/Editor.tsx

@@ -1934,18 +1934,18 @@ export const Editor = forwardRef<EditorHandle, EditorProps>(function Editor(
       {searchMode && (
         <div ref={searchUiRef}>
           <div className={styles.searchBar}>
-            <span className={styles.searchLabel}>reverse-i-search:</span>
+            <span className={styles.searchLabel}>
+              {t('editor.searchLabel')}
+            </span>
             <input
               ref={searchInputRef}
               className={styles.searchInput}
               value={searchQuery}
               onChange={handleSearchInput}
               onKeyDown={handleSearchKeyDown}
-              placeholder="type to search..."
+              placeholder={t('editor.searchPlaceholder')}
             />
-            <span className={styles.searchHint}>
-              ctrl+r next · tab accept · enter send · esc cancel
-            </span>
+            <span className={styles.searchHint}>{t('editor.searchHint')}</span>
           </div>
           {searchMatches.length > 0 && (
             <div className={styles.searchResults}>

packages/web-shell/client/components/ToastHost.tsx

@@ -1,4 +1,5 @@
 import { useEffect } from 'react';
+import { useI18n } from '../i18n';
 import styles from './ToastHost.module.css';
 
 export type ToastTone = 'info' | 'warning' | 'error' | 'success';
@@ -44,6 +45,7 @@ function ToastItem({
   onDismiss: (id: string) => void;
   autoDismissMs: number;
 }) {
+  const { t } = useI18n();
   useEffect(() => {
     const timer = window.setTimeout(() => onDismiss(toast.id), autoDismissMs);
     return () => window.clearTimeout(timer);
@@ -56,8 +58,8 @@ function ToastItem({
         type="button"
         className={styles.close}
         onClick={() => onDismiss(toast.id)}
-        aria-label="Dismiss notification"
-        title="Dismiss"
+        aria-label={t('toast.dismiss')}
+        title={t('toast.dismissShort')}
       >
         x
       </button>

packages/web-shell/client/components/dialogs/ApprovalModeDialog.tsx

@@ -82,7 +82,7 @@ export function ApprovalModeDialog({
         <button
           className={dp('resume-picker-close')}
           onClick={onClose}
-          title="Close"
+          title={t('common.close')}
         >
           ESC
         </button>

packages/web-shell/client/components/dialogs/DeleteSessionDialog.tsx

@@ -288,7 +288,7 @@ export function DeleteSessionDialog({
         <button
           className={dp('resume-picker-close')}
           onClick={onClose}
-          title="Close"
+          title={t('common.close')}
         >
           ESC
         </button>

packages/web-shell/client/components/dialogs/HelpDialog.tsx

@@ -311,7 +311,7 @@ export function HelpDialog({ commands, onClose }: HelpDialogProps) {
         <button
           className={dp('resume-picker-close')}
           onClick={onClose}
-          title="Close"
+          title={t('common.close')}
         >
           ESC
         </button>

packages/web-shell/client/components/dialogs/McpDialog.tsx

@@ -464,7 +464,7 @@ export function McpDialog({ onClose }: McpDialogProps) {
         <button
           className={dp('resume-picker-close')}
           onClick={onClose}
-          title="Close"
+          title={t('common.close')}
         >
           ESC
         </button>

packages/web-shell/client/components/dialogs/MemoryDialog.tsx

@@ -370,7 +370,7 @@ export function MemoryDialog({
         <button
           className={dp('resume-picker-close')}
           onClick={onClose}
-          title="Close"
+          title={t('common.close')}
         >
           ESC
         </button>

packages/web-shell/client/components/dialogs/ReleaseSessionDialog.tsx

@@ -191,7 +191,7 @@ export function ReleaseSessionDialog({
         <button
           className={dp('resume-picker-close')}
           onClick={onClose}
-          title="Close"
+          title={t('common.close')}
         >
           ESC
         </button>

packages/web-shell/client/components/dialogs/ResumeDialog.tsx

@@ -138,7 +138,7 @@ export function ResumeDialog({ onSelect, onClose }: ResumeDialogProps) {
         <button
           className={dp('resume-picker-close')}
           onClick={onClose}
-          title="Close"
+          title={t('common.close')}
         >
           ESC
         </button>

packages/web-shell/client/components/dialogs/SkillsDialog.tsx

@@ -95,7 +95,7 @@ export function SkillsDialog({ onClose }: SkillsDialogProps) {
         <button
           className={dp('resume-picker-close')}
           onClick={onClose}
-          title="Close"
+          title={t('common.close')}
         >
           ESC
         </button>

packages/web-shell/client/components/dialogs/ThemeDialog.tsx

@@ -77,7 +77,7 @@ export function ThemeDialog({
         <button
           className={dp('resume-picker-close')}
           onClick={onClose}
-          title="Close"
+          title={t('common.close')}
         >
           ESC
         </button>

packages/web-shell/client/components/messages/tools/SubAgentPanel.tsx

@@ -8,6 +8,7 @@ import {
 } from 'react';
 import type { ACPToolCall } from '../../../adapters/types';
 import { useWebShellCustomization } from '../../../customization';
+import { useI18n } from '../../../i18n';
 // Circular import with ToolGroup (agents render tool rows; agent tool
 // rows render SubAgentPanel). Safe only while both modules dereference
 // each other's exports at render time — never in top-level code.
@@ -159,6 +160,7 @@ type SubAgentTab = 'result' | 'tools';
  */
 function SubAgentStream({ text }: { text: string }) {
   const { compactThinking } = useWebShellCustomization();
+  const { t } = useI18n();
   const [streamExpanded, setStreamExpanded] = useState(false);
   const [overflowing, setOverflowing] = useState(false);
   const streamRef = useRef<HTMLPreElement>(null);
@@ -199,7 +201,7 @@ function SubAgentStream({ text }: { text: string }) {
           className={styles.expandToggle}
           onClick={() => setStreamExpanded((v) => !v)}
           aria-expanded={streamExpanded}
-          aria-label="Toggle agent stream details"
+          aria-label={t('subagent.toggleStream')}
         >
           {streamExpanded ? '▲' : '▼'}
         </button>

packages/web-shell/client/i18n.tsx

@@ -162,6 +162,9 @@ const EN: Messages = {
   'agent.view': 'View',
   'agents.closed': 'Agents panel closed.',
   'agents.title': 'Agents',
+  'subagent.toggleStream': 'Toggle agent stream details',
+  'toast.dismiss': 'Dismiss notification',
+  'toast.dismissShort': 'Dismiss',
   'insight.ready': 'Insight report generated successfully!',
   'request.cancelled': 'Request cancelled.',
   'approval.execQuestion': (v) => `Allow execution of: '${v?.tool ?? ''}'?`,
@@ -306,6 +309,9 @@ const EN: Messages = {
   'editor.noHistory': 'No matching history',
   'editor.placeholder': 'Type a message or @ file path',
   'editor.processing': 'Processing. New messages will be queued.',
+  'editor.searchHint': 'ctrl+r next · tab accept · enter send · esc cancel',
+  'editor.searchLabel': 'reverse-i-search:',
+  'editor.searchPlaceholder': 'type to search...',
   'error.unsupportedTheme':
     'Unsupported theme. Use /theme light or /theme dark.',
   'queue.cleared': 'Queued messages cleared',
@@ -1020,6 +1026,9 @@ const ZH: Messages = {
   'agent.view': '查看',
   'agents.closed': '智能体面板已关闭。',
   'agents.title': '智能体',
+  'subagent.toggleStream': '展开/收起子智能体详情',
+  'toast.dismiss': '关闭通知',
+  'toast.dismissShort': '关闭',
   'insight.ready': 'Insight 报告已生成！',
   'request.cancelled': '请求已取消。',
   'approval.execQuestion': (v) => `允许执行：'${v?.tool ?? ''}'？`,
@@ -1151,6 +1160,9 @@ const ZH: Messages = {
   'editor.noHistory': '没有匹配的历史记录',
   'editor.placeholder': '输入消息或 @ 文件路径',
   'editor.processing': '处理中。新消息会进入队列。',
+  'editor.searchHint': 'ctrl+r 下一条 · tab 采纳 · enter 发送 · esc 取消',
+  'editor.searchLabel': '历史搜索：',
+  'editor.searchPlaceholder': '输入以搜索…',
   'error.unsupportedTheme':
     '不支持该主题。请使用 /theme light 或 /theme dark。',
   'queue.cleared': '已清空排队消息',