feat(frontend): implement unified MCP panel for v3.7.0

Complete Phase 3 (P0) frontend implementation for unified MCP management:

**New Files:**
- src/hooks/useMcp.ts: React Query hooks for unified MCP operations
- src/components/mcp/UnifiedMcpPanel.tsx: Unified MCP management panel
- src/components/ui/checkbox.tsx: Checkbox component from shadcn/ui

**Features:**
- Unified panel with three-column layout: server info + app checkboxes + actions
- Multi-app control: Claude/Codex/Gemini checkboxes for each server
- Real-time stats: Show enabled server counts per app
- Full CRUD operations: Add, edit, delete, sync all servers

**Integration:**
- Replace old app-specific McpPanel with UnifiedMcpPanel in App.tsx
- Update McpFormModal to support unified mode with apps field
- Add i18n support: mcp.unifiedPanel namespace (zh/en)

**Type Safety:**
- Ensure McpServer.apps field always initialized
- Fix all test files to include apps field
- TypeScript type check passes ✅

**Architecture:**
- Single source of truth: mcp.servers manages all MCP configs
- Per-server app control: apps.claude/codex/gemini boolean flags
- Backward compatible: McpFormModal supports both unified and legacy modes

Next: P1 tasks (import dialogs, sub-components, tests)

src/components/mcp/McpFormModal.tsx

@@ -34,6 +34,7 @@ import {
 } from "@/utils/tomlUtils";
 import { normalizeTomlText } from "@/utils/textNormalization";
 import { useMcpValidation } from "./useMcpValidation";
+import { useUpsertMcpServer } from "@/hooks/useMcp";
 
 interface McpFormModalProps {
   appId: AppId;
@@ -46,6 +47,7 @@ interface McpFormModalProps {
   ) => Promise<void>;
   onClose: () => void;
   existingIds?: string[];
+  unified?: boolean; // 统一模式：使用 useUpsertMcpServer 而非传统回调
 }
 
 /**
@@ -60,11 +62,15 @@ const McpFormModal: React.FC<McpFormModalProps> = ({
   onSave,
   onClose,
   existingIds = [],
+  unified = false,
 }) => {
   const { t } = useTranslation();
   const { formatTomlError, validateTomlConfig, validateJsonConfig } =
     useMcpValidation();
 
+  // 统一模式下使用 mutation
+  const upsertMutation = useUpsertMcpServer();
+
   const [formId, setFormId] = useState(
     () => editingId || initialData?.id || "",
   );
@@ -361,24 +367,32 @@ const McpFormModal: React.FC<McpFormModalProps> = ({
 
     setSaving(true);
     try {
+      // 先处理 name 字段（必填）
+      const nameTrimmed = (formName || trimmedId).trim();
+      const finalName = nameTrimmed || trimmedId;
+
       const entry: McpServer = {
         ...(initialData ? { ...initialData } : {}),
         id: trimmedId,
+        name: finalName,
         server: serverSpec,
+        // 确保 apps 字段始终存在（v3.7.0 新架构必需）
+        apps: initialData?.apps || { claude: false, codex: false, gemini: false },
       };
 
-      // 修复：新增 MCP 时默认启用（enabled=true）
-      // 编辑模式下保留原有的 enabled 状态
-      if (initialData?.enabled !== undefined) {
-        entry.enabled = initialData.enabled;
-      } else {
-        // 新增模式：默认启用
-        entry.enabled = true;
+      // 统一模式下无需再初始化 apps（上面已经处理）
+      // 传统模式需要设置 enabled 字段
+      if (!unified) {
+        // 传统模式：新增 MCP 时默认启用（enabled=true）
+        // 编辑模式下保留原有的 enabled 状态
+        if (initialData?.enabled !== undefined) {
+          entry.enabled = initialData.enabled;
+        } else {
+          // 新增模式：默认启用
+          entry.enabled = true;
+        }
       }
 
-      const nameTrimmed = (formName || trimmedId).trim();
-      entry.name = nameTrimmed || trimmedId;
-
       const descriptionTrimmed = formDescription.trim();
       if (descriptionTrimmed) {
         entry.description = descriptionTrimmed;
@@ -410,8 +424,16 @@ const McpFormModal: React.FC<McpFormModalProps> = ({
         delete entry.tags;
       }
 
-      // 显式等待父组件保存流程
-      await onSave(trimmedId, entry, { syncOtherSide });
+      // 显式等待保存流程
+      if (unified) {
+        // 统一模式：调用 useUpsertMcpServer mutation
+        await upsertMutation.mutateAsync(entry);
+        toast.success(t("common.success"));
+        onClose();
+      } else {
+        // 传统模式：调用父组件回调
+        await onSave(trimmedId, entry, { syncOtherSide });
+      }
     } catch (error: any) {
       const detail = extractErrorMessage(error);
       const mapped = translateMcpBackendError(detail, t);