Q174: choosing a language no longer restarts the app; the restart waits for the user

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/renderer/src/i18n/zh.ts

@@ -696,6 +696,12 @@ export const zh: Record<string, string> = {
   "Resets {date} (UTC)": "{date} 重置（UTC）",
   "Unsaved": "未保存",
   "Working language": "工作语言",
+  "{language} applies after a restart.": "{language} 将在重启后生效。",
+  "Restart now": "立即重启",
+  "Restart to switch language?": "重启以切换语言？",
+  "Text you typed but have not sent or saved is lost.": "已输入但尚未发送或保存的文字会丢失。",
+  "Running agent sessions: {count}. They stop now; their tasks stay open and start a new session when next queued, by heartbeat or Run, and a chat reply in progress is not sent.": "运行中的 Agent 会话：{count}。它们会立即停止；其任务保持未完成，并在下次通过心跳或“运行”排队时开始新会话，进行中的聊天回复不会发出。",
+  "Counting running agent sessions…": "正在统计运行中的 Agent 会话…",
   "Company default ({language})": "公司默认（{language}）",
   "Agents' working language": "Agent 工作语言",
   "Agents write messages, tasks, documents and deliverables in it. The display language does not change it, and a task can set its own.": "Agent 用它撰写消息、任务、文档和交付物。显示语言不会改变它，单个任务也可以单独设置。",

src/renderer/src/pages/settings/LanguageField.tsx

@@ -0,0 +1,58 @@
+import { useState } from "react";
+import type { UiLanguage, UiPreferences } from "../../../../shared/domain";
+import type { SnapshotActions } from "../../app/useSnapshot";
+import { Dialog } from "../../shared/Dialog";
+import { Button, Field } from "../../shared/ui";
+import { t } from "../../i18n/i18n";
+
+const NAMES: Record<UiLanguage, string> = { en: "English", zh: "中文" };
+
+/** The display language is fixed per launch, so a choice waits for a restart the user starts after seeing what it interrupts. */
+export function LanguageField({ uiPreferences, actions }: { uiPreferences: UiPreferences; actions: SnapshotActions }) {
+  const [confirming, setConfirming] = useState(false);
+  const [running, setRunning] = useState<number | null>(null);
+  const [error, setError] = useState<string | null>(null);
+  const confirm = () => {
+    setRunning(null);
+    setError(null);
+    setConfirming(true);
+    void window.agentCompany.runningSessionCount().then((result) => {
+      if (result.ok) setRunning(result.data);
+      else setError(result.error.message);
+    });
+  };
+  const pending = uiPreferences.language !== window.agentCompany.language;
+  const restart = () => {
+    setError(null);
+    void window.agentCompany.relaunchApp().then((result) => { if (!result.ok) setError(result.error.message); });
+  };
+  return (
+    <Field label={t("Language")}>
+      <select
+        className="input"
+        aria-label={t("Language")}
+        value={uiPreferences.language}
+        onChange={(event) => void actions.run(() => window.agentCompany.setUiPreferences({ language: event.target.value as UiLanguage }))}
+      >
+        <option value="en">{NAMES.en}</option>
+        <option value="zh">{NAMES.zh}</option>
+      </select>
+      <span style={{ fontSize: 12, color: "var(--text-3)" }}>{t("Changes only what you see; agents keep the company's working language.")}</span>
+      {pending && (
+        <span className="row" style={{ gap: 8, fontSize: 12 }} role="status">
+          {t("{language} applies after a restart.", { language: NAMES[uiPreferences.language] })}
+          <Button size="small" onClick={confirm}>{t("Restart now")}</Button>
+        </span>
+      )}
+      <Dialog title={t("Restart to switch language?")} open={confirming} submitLabel={t("Restart now")} onClose={() => setConfirming(false)} onSubmit={(event) => { event.preventDefault(); restart(); }}>
+        <ul style={{ margin: 0, paddingLeft: 18, lineHeight: 1.6, fontSize: 13 }}>
+          <li>{t("Text you typed but have not sent or saved is lost.")}</li>
+          <li>{running === null
+            ? t("Counting running agent sessions…")
+            : t("Running agent sessions: {count}. They stop now; their tasks stay open and start a new session when next queued, by heartbeat or Run, and a chat reply in progress is not sent.", { count: running })}</li>
+        </ul>
+        {error && <div className="form-error" role="alert">{error}</div>}
+      </Dialog>
+    </Field>
+  );
+}

src/renderer/src/pages/settings/WorkspacePanel.tsx

@@ -1,3 +1,4 @@
+import { LanguageField } from "./LanguageField";
 import { WorkspaceRow } from "./WorkspaceRow";
 import { CompanyDialog } from "./CompanyDialog";
 import { ScopeNote } from "./ScopeNote";
@@ -5,7 +6,6 @@ import { useState, type FormEvent } from "react";
 import type {
   OrganizationRecord,
   ProjectRecord,
-  UiLanguage,
   UiPreferences,
   UiTheme,
   WorkspaceRecord,
@@ -102,20 +102,7 @@ export function WorkspacePanel({
             <option value="dark">{t("Dark")}</option>
           </select>
         </Field>
-        <Field label={t("Language")}>
-          <select
-            className="input"
-            aria-label={t("Language")}
-            value={uiPreferences.language}
-            onChange={(event) =>
-              void actions.run(() => window.agentCompany.setUiPreferences({ language: event.target.value as UiLanguage }))
-            }
-          >
-            <option value="en">English</option>
-            <option value="zh">中文</option>
-          </select>
-          <span style={{ fontSize: 12, color: "var(--text-3)" }}>{t("Changes only what you see; agents keep the company's working language.")}</span>
-        </Field>
+        <LanguageField uiPreferences={uiPreferences} actions={actions} />
       </div>
 
       <div className="row reveal-row" style={{ marginBottom: 8 }}>