✨ feat(connection-import): 支持导入 Navicat NCX 连接与密码

- 新增 Navicat NCX XML 解析与 v1/v2 密码解密能力
- 接入后端连接导入链路并补充导入失败提示
- 前端补充 NCX 格式识别、缺失密码提示与定向测试

frontend/src/utils/connectionExport.ts

@@ -1,6 +1,6 @@
 import type { ConnectionConfig, SavedConnection } from '../types';
 
-export type ConnectionImportKind = 'app-managed-package' | 'encrypted-package' | 'legacy-json' | 'mysql-workbench-xml' | 'invalid';
+export type ConnectionImportKind = 'app-managed-package' | 'encrypted-package' | 'legacy-json' | 'mysql-workbench-xml' | 'navicat-ncx' | 'invalid';
 export type ConnectionPackageDialogSnapshot = {
   open: boolean;
   mode: 'export' | 'import';
@@ -109,10 +109,19 @@ const isMySQLWorkbenchXML = (raw: string): boolean => (
   raw.includes('<data') && raw.includes('grt_format') && raw.includes('db.mgmt.Connection')
 );
 
+const isNavicatNCX = (raw: string): boolean => (
+  raw.includes('<Connection')
+  && raw.includes('ConnType=')
+  && raw.includes('ConnectionName=')
+);
+
 export const detectConnectionImportKind = (raw: unknown): ConnectionImportKind => {
   if (typeof raw === 'string' && isMySQLWorkbenchXML(raw)) {
     return 'mysql-workbench-xml';
   }
+  if (typeof raw === 'string' && isNavicatNCX(raw)) {
+    return 'navicat-ncx';
+  }
 
   const parsed = parseConnectionImportRaw(raw);