fix(service-party-app): 创建会话时添加 initiator_party_id 参数

- CreateKeygenSessionRequest 添加 initiator_party_id 和 initiator_name 字段
- 创建会话前检查是否已连接到消息路由器
- 自动获取已注册的 partyId 作为发起者

🤖 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

@@ -192,10 +192,18 @@ function setupIpcHandlers() {
   // gRPC - 创建会话 (通过 Account 服务 HTTP API)
   ipcMain.handle('grpc:createSession', async (_event, params) => {
     try {
+      // 获取当前 party ID
+      const partyId = grpcClient?.getPartyId();
+      if (!partyId) {
+        return { success: false, error: '请先连接到消息路由器' };
+      }
+
       const result = await accountClient?.createKeygenSession({
         wallet_name: params.walletName,
         threshold_t: params.thresholdT,
         threshold_n: params.thresholdN,
+        initiator_party_id: partyId,
+        initiator_name: params.initiatorName || '发起者',
         persistent_count: 0, // 服务端 party 数量，共管钱包模式下为 0
         external_count: params.thresholdN, // 所有参与方都是外部 party
         expires_in_seconds: 86400, // 24 小时

backend/mpc-system/services/service-party-app/electron/modules/account-client.ts

@@ -14,6 +14,8 @@ export interface CreateKeygenSessionRequest {
   wallet_name: string;
   threshold_t: number;
   threshold_n: number;
+  initiator_party_id: string;
+  initiator_name?: string;
   persistent_count: number;
   external_count: number;
   expires_in_seconds?: number;