fix(mcp): improve error message internationalization

- Add translateMcpBackendError utility to map backend errors to i18n keys
- Update error handling in McpPanel, McpFormModal, and McpWizardModal
- Internationalize stdio/http type selectors in Wizard
- Implement three-tier fallback strategy: translation → raw error → default message
- No backend changes required, fully frontend-based i18n implementation

src/components/SettingsModal.tsx

@@ -389,7 +389,11 @@ export default function SettingsModal({
       const filePath = await window.api.saveFileDialog(defaultName);
 
       if (!filePath) {
-        onNotify?.(`${t("settings.exportFailed")}: ${t("settings.selectFileFailed")}`, "error", 4000);
+        onNotify?.(
+          `${t("settings.exportFailed")}: ${t("settings.selectFileFailed")}`,
+          "error",
+          4000,
+        );
         return;
       }
 

src/components/mcp/McpFormModal.tsx

@@ -5,7 +5,10 @@ import { McpServer } from "../../types";
 import { mcpPresets } from "../../config/mcpPresets";
 import { buttonStyles, inputStyles } from "../../lib/styles";
 import McpWizardModal from "./McpWizardModal";
-import { extractErrorMessage } from "../../utils/errorUtils";
+import {
+  extractErrorMessage,
+  translateMcpBackendError,
+} from "../../utils/errorUtils";
 import { AppType } from "../../lib/tauri-api";
 import {
   validateToml,
@@ -335,8 +338,9 @@ const McpFormModal: React.FC<McpFormModalProps> = ({
       await onSave(formId.trim(), server);
     } catch (error: any) {
       const detail = extractErrorMessage(error);
-      const msg = detail || t("mcp.error.saveFailed");
-      onNotify?.(msg, "error", detail ? 6000 : 4000);
+      const mapped = translateMcpBackendError(detail, t);
+      const msg = mapped || detail || t("mcp.error.saveFailed");
+      onNotify?.(msg, "error", mapped || detail ? 6000 : 4000);
     } finally {
       setSaving(false);
     }

src/components/mcp/McpPanel.tsx

@@ -5,7 +5,10 @@ import { McpServer } from "../../types";
 import McpListItem from "./McpListItem";
 import McpFormModal from "./McpFormModal";
 import { ConfirmDialog } from "../ConfirmDialog";
-import { extractErrorMessage } from "../../utils/errorUtils";
+import {
+  extractErrorMessage,
+  translateMcpBackendError,
+} from "../../utils/errorUtils";
 // 预设相关逻辑已迁移到“新增 MCP”面板，列表此处无需引用
 import { buttonStyles } from "../../lib/styles";
 import { AppType } from "../../lib/tauri-api";
@@ -89,10 +92,11 @@ const McpPanel: React.FC<McpPanelProps> = ({ onClose, onNotify, appType }) => {
       // 失败时回滚
       setServers(previousServers);
       const detail = extractErrorMessage(e);
+      const mapped = translateMcpBackendError(detail, t);
       onNotify?.(
-        detail || t("mcp.error.saveFailed"),
+        mapped || detail || t("mcp.error.saveFailed"),
         "error",
-        detail ? 6000 : 5000,
+        mapped || detail ? 6000 : 5000,
       );
     }
   };
@@ -120,10 +124,11 @@ const McpPanel: React.FC<McpPanelProps> = ({ onClose, onNotify, appType }) => {
           onNotify?.(t("mcp.msg.deleted"), "success", 1500);
         } catch (e: any) {
           const detail = extractErrorMessage(e);
+          const mapped = translateMcpBackendError(detail, t);
           onNotify?.(
-            detail || t("mcp.error.deleteFailed"),
+            mapped || detail || t("mcp.error.deleteFailed"),
             "error",
-            detail ? 6000 : 5000,
+            mapped || detail ? 6000 : 5000,
           );
         }
       },
@@ -139,10 +144,11 @@ const McpPanel: React.FC<McpPanelProps> = ({ onClose, onNotify, appType }) => {
       onNotify?.(t("mcp.msg.saved"), "success", 1500);
     } catch (e: any) {
       const detail = extractErrorMessage(e);
+      const mapped = translateMcpBackendError(detail, t);
       onNotify?.(
-        detail || t("mcp.error.saveFailed"),
+        mapped || detail || t("mcp.error.saveFailed"),
         "error",
-        detail ? 6000 : 5000,
+        mapped || detail ? 6000 : 5000,
       );
       // 继续抛出错误，让表单层可以给到直观反馈（避免被更高层遮挡）
       throw e;

src/components/mcp/McpWizardModal.tsx

@@ -227,7 +227,7 @@ const McpWizardModal: React.FC<McpWizardModalProps> = ({
                     className="w-4 h-4 text-emerald-500 bg-white dark:bg-gray-800 border-gray-200 dark:border-gray-700 focus:ring-emerald-500 dark:focus:ring-emerald-400 focus:ring-2"
                   />
                   <span className="text-sm text-gray-900 dark:text-gray-100">
-                    stdio
+                    {t("mcp.wizard.typeStdio")}
                   </span>
                 </label>
                 <label className="inline-flex items-center gap-2 cursor-pointer">
@@ -241,7 +241,7 @@ const McpWizardModal: React.FC<McpWizardModalProps> = ({
                     className="w-4 h-4 text-emerald-500 bg-white dark:bg-gray-800 border-gray-200 dark:border-gray-700 focus:ring-emerald-500 dark:focus:ring-emerald-400 focus:ring-2"
                   />
                   <span className="text-sm text-gray-900 dark:text-gray-100">
-                    http
+                    {t("mcp.wizard.typeHttp")}
                   </span>
                 </label>
               </div>