✨ feat(connection): 增强连接管理与交互体验

- 新增测试连接功能，修复底层驱动假成功问题，确保密码/端口验证准确
- 支持导入/导出连接配置（JSON），便于迁移与备份
- 优化侧边栏：实现虚拟滚动解决卡顿，增加数据库筛选与断开连接重连机制
- 优化交互：改进右键菜单体验（全行触发/禁用选文），完善新建查询的上下文自动关联
- 界面调整：精简连接弹窗，移除冗余的默认数据库输入

frontend/wailsjs/go/app/App.d.ts

@@ -30,6 +30,8 @@ export function ExportData(arg1:Array<Record<string, any>>,arg2:Array<string>,ar
 
 export function ExportTable(arg1:connection.ConnectionConfig,arg2:string,arg3:string,arg4:string):Promise<connection.QueryResult>;
 
+export function ImportConfigFile():Promise<connection.QueryResult>;
+
 export function ImportData(arg1:connection.ConnectionConfig,arg2:string,arg3:string):Promise<connection.QueryResult>;
 
 export function MySQLConnect(arg1:connection.ConnectionConfig):Promise<connection.QueryResult>;
@@ -43,3 +45,5 @@ export function MySQLQuery(arg1:connection.ConnectionConfig,arg2:string,arg3:str
 export function MySQLShowCreateTable(arg1:connection.ConnectionConfig,arg2:string,arg3:string):Promise<connection.QueryResult>;
 
 export function OpenSQLFile():Promise<connection.QueryResult>;
+
+export function TestConnection(arg1:connection.ConnectionConfig):Promise<connection.QueryResult>;

frontend/wailsjs/go/app/App.js

@@ -58,6 +58,10 @@ export function ExportTable(arg1, arg2, arg3, arg4) {
   return window['go']['app']['App']['ExportTable'](arg1, arg2, arg3, arg4);
 }
 
+export function ImportConfigFile() {
+  return window['go']['app']['App']['ImportConfigFile']();
+}
+
 export function ImportData(arg1, arg2, arg3) {
   return window['go']['app']['App']['ImportData'](arg1, arg2, arg3);
 }
@@ -85,3 +89,7 @@ export function MySQLShowCreateTable(arg1, arg2, arg3) {
 export function OpenSQLFile() {
   return window['go']['app']['App']['OpenSQLFile']();
 }
+
+export function TestConnection(arg1) {
+  return window['go']['app']['App']['TestConnection'](arg1);
+}