fix(session-coordinator): 保存 WalletName 和 InviteCode 到数据库

- CreateSessionInput 添加 WalletName 和 InviteCode 字段
- gRPC handler 从请求中读取并传递这些字段
- CreateSession use case 在创建会话时设置这些字段

修复: 通过邀请码查询会话时找不到记录的问题

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

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

backend/mpc-system/services/session-coordinator/adapters/input/grpc/session_grpc_handler.go

@@ -159,6 +159,8 @@ func (s *SessionCoordinatorServer) CreateSession(
 		Participants: participants,
 		MessageHash:  req.MessageHash,
 		ExpiresIn:    time.Duration(req.ExpiresInSeconds) * time.Second,
+		WalletName:   req.WalletName,
+		InviteCode:   req.InviteCode,
 	}
 
 	// Parse and set keygen_session_id if provided (for signing sessions)

backend/mpc-system/services/session-coordinator/application/ports/input/session_management_port.go

@@ -55,6 +55,8 @@ type CreateSessionInput struct {
 	ExpiresIn         time.Duration
 	DelegateUserShare *DelegateUserShare // For sign sessions with delegate party
 	KeygenSessionID   uuid.UUID          // For sign sessions: which keygen session's shares to use
+	WalletName        string             // For co_managed_keygen: wallet name
+	InviteCode        string             // For co_managed_keygen: invite code for participants
 }
 
 // ParticipantInfo contains information about a participant

backend/mpc-system/services/session-coordinator/application/use_cases/create_session.go

@@ -138,6 +138,18 @@ func (uc *CreateSessionUseCase) Execute(
 			zap.String("keygen_session_id", req.KeygenSessionID.String()))
 	}
 
+	// 4.2 Set wallet name and invite code for co_managed_keygen sessions
+	if req.WalletName != "" {
+		session.WalletName = req.WalletName
+	}
+	if req.InviteCode != "" {
+		session.InviteCode = req.InviteCode
+		logger.Info("Co-managed keygen session created with invite code",
+			zap.String("session_id", session.ID.String()),
+			zap.String("wallet_name", req.WalletName),
+			zap.String("invite_code", req.InviteCode))
+	}
+
 	// 5. Add participants and generate join tokens
 	tokens := make(map[string]string)
 	if len(req.Participants) == 0 {