fix(service-party-app): 修复gRPC测试连接方法

将testConnection从URL解析改为直接使用host:port格式,
与grpc-client.ts的connect方法保持一致。

地址格式: mpc-grpc.szaiai.com:443 (自动检测TLS)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/mpc-system/services/service-party-app/electron/main.ts

@@ -223,9 +223,8 @@ function setupIpcHandlers() {
   // gRPC - 测试连接
   ipcMain.handle('grpc:testConnection', async (_event, { url }) => {
     try {
-      // 解析 URL
-      const urlObj = new URL(url);
-      await grpcClient?.connect(urlObj.hostname, parseInt(urlObj.port) || 50051);
+      // 地址格式: host:port (例如 mpc-grpc.szaiai.com:443)
+      await grpcClient?.connect(url);
       return { success: true };
     } catch (error) {
       return { success: false, error: (error as Error).message };