feat(i18n): localize backend (main-process) strings, default Chinese

src/main/claude/agent-runner-message-end.ts

@@ -6,6 +6,7 @@ import type {
   ToolCall,
 } from '@mariozechner/pi-ai';
 import { splitThinkTagBlocks } from './think-tag-parser';
+import { mt } from '../i18n';
 
 type MessageEndContentBlock = TextContent | ThinkingContent | ToolCall;
 
@@ -43,31 +44,31 @@ export type AbortDisposition = 'timeout' | 'loop_guard' | 'stream_error' | 'user
 export function toUserFacingErrorText(errorText: string): string {
   const lower = errorText.toLowerCase();
   if (lower.includes('first_response_timeout')) {
-    return '模型响应超时：长时间未收到上游返回，请稍后重试或检查当前模型/网关负载。';
+    return mt('errModelTimeout');
   }
   if (lower.includes('empty_success_result')) {
-    return '模型返回了一个空的成功结果，当前模型或网关兼容性可能有问题，请重试或切换协议后再试。';
+    return mt('errEmptySuccess');
   }
   if (
     /\b400\b/.test(errorText) ||
     lower.includes('bad request') ||
     lower.includes('invalid request')
   ) {
-    return `请求被上游拒绝（400），可能是模型/协议配置不兼容。请检查模型名称、协议设置和 API 端点。\n原始错误: ${errorText}`;
+    return mt('errBadRequest', { error: errorText });
   }
   if (
     /\b(401|403)\b/.test(errorText) ||
     lower.includes('unauthorized') ||
     lower.includes('forbidden')
   ) {
-    return `认证失败，请检查 API Key 是否正确、是否已过期或无权访问当前模型。\n原始错误: ${errorText}`;
+    return mt('errAuthFailed', { error: errorText });
   }
   if (
     /\b429\b/.test(errorText) ||
     lower.includes('rate limit') ||
     lower.includes('too many requests')
   ) {
-    return `请求被限流（429），当前模型或 API 端点的调用频率已达上限，请稍后重试。\n原始错误: ${errorText}`;
+    return mt('errRateLimited', { error: errorText });
   }
   if (
     /\b(5\d{2})\b/.test(errorText) ||
@@ -76,7 +77,7 @@ export function toUserFacingErrorText(errorText: string): string {
     lower.includes('service unavailable') ||
     lower.includes('overloaded')
   ) {
-    return `上游服务异常，可能是模型服务过载或临时故障，SDK 将自动重试。\n原始错误: ${errorText}`;
+    return mt('errUpstreamError', { error: errorText });
   }
   if (
     lower.includes('terminated') ||
@@ -90,7 +91,7 @@ export function toUserFacingErrorText(errorText: string): string {
     lower.includes('upstream connect') ||
     lower.includes('retry delay')
   ) {
-    return `网络连接中断（${errorText}），可能是代理/网关不稳定，SDK 将自动重试。`;
+    return mt('errNetworkInterrupted', { error: errorText });
   }
   return errorText;
 }
@@ -104,9 +105,7 @@ export function resolveAssistantStreamErrorText(
 
 export function buildTerminalErrorMessage(errorText: string, partialText = ''): string {
   const normalizedPartial = partialText.trimEnd();
-  const hint = FOUR_XX_ERROR_RE.test(errorText)
-    ? '_请检查配置后重试。_'
-    : '_Agent 正在自动重试，请稍候..._';
+  const hint = FOUR_XX_ERROR_RE.test(errorText) ? mt('errCheckConfigHint') : mt('errRetryingHint');
   const errorBlock = `**Error**: ${errorText}\n\n${hint}`;
   return normalizedPartial ? `${normalizedPartial}\n\n${errorBlock}` : errorBlock;
 }

src/main/config/config-store.ts

@@ -30,6 +30,7 @@ import {
   shouldUseAnthropicAuthToken,
 } from './auth-utils';
 import { API_PROVIDER_PRESETS, PI_AI_CURATED_PRESETS } from '../../shared/api-model-presets';
+import { mt, setBackendLanguage, DEFAULT_BACKEND_LANGUAGE } from '../i18n';
 
 /**
  * Application configuration schema
@@ -112,6 +113,10 @@ export interface AppConfig {
   // UI theme preference
   theme: AppTheme;
 
+  // UI language. Mirrors the renderer's active react-i18next language and drives
+  // backend (main-process) strings via setBackendLanguage(). Defaults to Chinese.
+  uiLanguage?: string;
+
   // Sandbox mode (WSL/Lima isolation)
   sandboxEnabled: boolean;
 
@@ -218,7 +223,7 @@ const defaultProfiles: Record<ProviderProfileKey, ProviderProfile> = {
 
 const defaultConfigSet: ApiConfigSet = {
   id: DEFAULT_CONFIG_SET_ID,
-  name: '默认方案',
+  name: mt('configDefaultSetName'),
   isSystem: true,
   provider: 'openrouter',
   customProtocol: 'anthropic',
@@ -243,6 +248,7 @@ const defaultConfig: AppConfig = {
   globalSkillsPath: '',
   enableDevLogs: false,
   theme: 'light',
+  uiLanguage: DEFAULT_BACKEND_LANGUAGE,
   sandboxEnabled: false,
   memoryEnabled: true,
   memoryRuntime: {
@@ -539,6 +545,9 @@ export class ConfigStore {
       warn: logWarn,
     }) as unknown as Store<AppConfig>;
     this.ensureNormalized();
+    // Seed the backend translator from the persisted UI language so main-process
+    // strings (errors, dialogs) match the user's last choice from first launch.
+    setBackendLanguage((this.store.store as AppConfig).uiLanguage);
   }
 
   private ensureNormalized(): void {
@@ -858,7 +867,7 @@ export class ConfigStore {
 
       const normalizedSet = this.normalizeConfigSet(rawSet, {
         id: nextId,
-        name: toNonEmptyString(rawSet.name) || `方案 ${index + 1}`,
+        name: toNonEmptyString(rawSet.name) || mt('configFallbackSetName', { index: index + 1 }),
         provider: legacy.provider,
         customProtocol: legacy.customProtocol,
         activeProfileKey: legacy.activeProfileKey,
@@ -974,6 +983,10 @@ export class ConfigStore {
           : defaultConfig.globalSkillsPath,
       enableDevLogs: toBoolean(raw.enableDevLogs, defaultConfig.enableDevLogs),
       theme: isAppTheme(raw.theme) ? raw.theme : defaultConfig.theme,
+      uiLanguage:
+        typeof raw.uiLanguage === 'string' && raw.uiLanguage.trim()
+          ? raw.uiLanguage
+          : defaultConfig.uiLanguage,
       sandboxEnabled: toBoolean(raw.sandboxEnabled, defaultConfig.sandboxEnabled),
       memoryEnabled: toBoolean(raw.memoryEnabled, defaultConfig.memoryEnabled),
       memoryRuntime: normalizeMemoryRuntimeConfig(raw.memoryRuntime),
@@ -995,6 +1008,8 @@ export class ConfigStore {
   private saveConfig(config: AppConfig): void {
     const normalized = this.normalizeConfig(config);
     this.store.set(normalized);
+    // Keep the backend translator in sync when the UI language changes.
+    setBackendLanguage(normalized.uiLanguage);
   }
 
   private composeProjectedConfig(
@@ -1388,6 +1403,7 @@ export class ConfigStore {
       enableDevLogs:
         updates.enableDevLogs !== undefined ? updates.enableDevLogs : current.enableDevLogs,
       theme: updates.theme !== undefined ? updates.theme : current.theme,
+      uiLanguage: updates.uiLanguage !== undefined ? updates.uiLanguage : current.uiLanguage,
       sandboxEnabled:
         updates.sandboxEnabled !== undefined ? updates.sandboxEnabled : current.sandboxEnabled,
       memoryEnabled: