refactor: 将客服后端重构为宿主可嵌入模块

- 注入数据库、运行时配置、统一响应、文件存储和平台 AI 能力，补充业务读写工具与客户快捷操作契约。

- 移除模块内重复的组织、客户、工单、标签、技能、旧工作流、MCP 和迁移实现，将身份权限与业务主体交由宿主管理。

- 使用 libSQL 重构向量存储，并完善图片消息、访客身份、排队调度、企业微信和支持聊天页面。

- 统一 HTTP、DTO 与 WebSocket 的 snake_case 协议，补齐模块初始化、业务动作和公共载荷等回归测试。

internal/services/conversation_service.go

@@ -84,12 +84,15 @@ func (s *conversationService) Updates(id int64, columns map[string]interface{})
 	return repositories.ConversationRepository.Updates(sqls.DB(), id, columns)
 }
 
-func (s *conversationService) getLatestNotFinishedByCustomerID(db *gorm.DB, customerID int64) *models.Conversation {
-	if customerID <= 0 {
+func (s *conversationService) getLatestNotFinishedByExternalUser(db *gorm.DB, externalUser openidentity.ExternalUser, channelID int64) *models.Conversation {
+	externalID := strings.TrimSpace(externalUser.ExternalID)
+	if externalID == "" || channelID <= 0 {
 		return nil
 	}
 	cnd := sqls.NewCnd()
-	cnd.Eq("customer_id", customerID)
+	cnd.Eq("channel_id", channelID)
+	cnd.Eq("customer_type", externalCustomerType(externalUser))
+	cnd.Eq("customer_external_id", externalID)
 	cnd.In("status", []enums.IMConversationStatus{
 		enums.IMConversationStatusAIServing,
 		enums.IMConversationStatusPending,
@@ -113,40 +116,67 @@ func (s *conversationService) Create(externalUser openidentity.ExternalUser, cha
 	var conversation *models.Conversation
 	var welcomeMessage *models.Message
 	created := false
+	reconfigured := false
 	if err := sqls.WithTransaction(func(ctx *sqls.TxContext) error {
-		customerID, err := CustomerService.EnsureExternalCustomer(ctx, externalUser)
-		if err != nil {
-			return err
+		customerType := externalCustomerType(externalUser)
+		customerID := externalUser.SubjectID
+		customerName := strings.TrimSpace(externalUser.ExternalName)
+		existing := s.getLatestNotFinishedByExternalUser(ctx.Tx, externalUser, channelID)
+		// A conversation already being handled by a human keeps its original
+		// service contract. If the channel was switched to another Agent/mode,
+		// start a new conversation with the latest config instead of silently
+		// reusing the stale human conversation.
+		if existing != nil && (existing.CurrentAssigneeID > 0 || existing.HandoffAt != nil) &&
+			(existing.AIAgentID != aiAgentID || existing.ServiceMode != serviceMode) {
+			existing = nil
 		}
-		customerName := s.getCustomerName(ctx.Tx, customerID)
-		if existing := s.getLatestNotFinishedByCustomerID(ctx.Tx, customerID); existing != nil {
+		if existing != nil {
 			conversation = existing
+			updates := make(map[string]any)
 			if customerName != "" && existing.CustomerName != customerName {
-				if err := repositories.ConversationRepository.Updates(ctx.Tx, existing.ID, map[string]any{
-					"customer_name": customerName,
-					"updated_at":    time.Now(),
-				}); err != nil {
+				updates["customer_name"] = customerName
+				conversation.CustomerName = customerName
+			}
+			// A channel binding may change after a conversation was created. Keep an
+			// unassigned conversation aligned with the latest channel/Agent config,
+			// while never taking a conversation away from a human or a handoff flow.
+			if existing.CurrentAssigneeID == 0 && existing.HandoffAt == nil &&
+				(existing.ChannelID != channelID || existing.AIAgentID != aiAgentID || existing.ServiceMode != serviceMode) {
+				updates["channel_id"] = channelID
+				updates["ai_agent_id"] = aiAgentID
+				updates["service_mode"] = serviceMode
+				updates["status"] = s.resolveInitialStatus(serviceMode)
+				conversation.ChannelID = channelID
+				conversation.AIAgentID = aiAgentID
+				conversation.ServiceMode = serviceMode
+				conversation.Status = s.resolveInitialStatus(serviceMode)
+				reconfigured = true
+			}
+			if len(updates) > 0 {
+				updates["updated_at"] = time.Now()
+				if err := repositories.ConversationRepository.Updates(ctx.Tx, existing.ID, updates); err != nil {
 					return err
 				}
-				conversation.CustomerName = customerName
 			}
 			return nil
 		}
 		created = true
 		now := time.Now()
 		conversation = &models.Conversation{
-			AIAgentID:         aiAgentID,
-			ChannelID:         channelID,
-			CustomerID:        customerID,
-			CustomerName:      customerName,
-			Status:            s.resolveInitialStatus(serviceMode),
-			ServiceMode:       serviceMode,
-			Priority:          0,
-			CurrentAssigneeID: 0,
-			CurrentTeamID:     0,
-			LastMessageAt:     now,
-			LastActiveAt:      now,
-			AuditFields:       utils.BuildAuditFields(nil),
+			AIAgentID:          aiAgentID,
+			ChannelID:          channelID,
+			CustomerType:       customerType,
+			CustomerID:         customerID,
+			CustomerExternalID: strings.TrimSpace(externalUser.ExternalID),
+			CustomerName:       customerName,
+			Status:             s.resolveInitialStatus(serviceMode),
+			ServiceMode:        serviceMode,
+			Priority:           0,
+			CurrentAssigneeID:  0,
+			CurrentTeamID:      0,
+			LastMessageAt:      now,
+			LastActiveAt:       now,
+			AuditFields:        utils.BuildAuditFields(nil),
 		}
 		if err := ctx.Tx.Create(conversation).Error; err != nil {
 			return err
@@ -158,8 +188,9 @@ func (s *conversationService) Create(externalUser openidentity.ExternalUser, cha
 			return err
 		}
 		if aiAgent != nil {
-			welcomeMessage, err = MessageService.createAIWelcomeMessage(ctx, conversation, aiAgent, now)
-			return err
+			var welcomeErr error
+			welcomeMessage, welcomeErr = MessageService.createAIWelcomeMessage(ctx, conversation, aiAgent, now)
+			return welcomeErr
 		}
 		return nil
 	}); err != nil {
@@ -169,7 +200,10 @@ func (s *conversationService) Create(externalUser openidentity.ExternalUser, cha
 		return nil, errorsx.BusinessErrorI18n(1, "error.conversation.createFailed")
 	}
 	if !created {
-		return conversation, nil
+		if reconfigured {
+			WsService.PublishConversationChanged(conversation, enums.IMRealtimeEventConversationUpdated)
+		}
+		return s.Get(conversation.ID), nil
 	}
 
 	// 推送会话创建事件
@@ -204,6 +238,7 @@ func (s *conversationService) AssignConversation(req request.AssignConversationR
 		return errorsx.InvalidParamI18n("error.e0276")
 	}
 	var assignedEvent events.ConversationAssignedEvent
+	var previousTeamID int64
 	if err := sqls.WithTransaction(func(ctx *sqls.TxContext) error {
 		conversation := repositories.ConversationRepository.Get(ctx.Tx, req.ConversationID)
 		if conversation == nil {
@@ -212,6 +247,7 @@ func (s *conversationService) AssignConversation(req request.AssignConversationR
 		if conversation.Status != enums.IMConversationStatusPending {
 			return errorsx.InvalidParamI18n("error.e0135")
 		}
+		previousTeamID = conversation.CurrentTeamID
 		now := time.Now()
 		if err := ConversationAssignmentService.FinishActiveAssignments(ctx, req.ConversationID, now); err != nil {
 			return err
@@ -221,6 +257,7 @@ func (s *conversationService) AssignConversation(req request.AssignConversationR
 		}
 		if err := repositories.ConversationRepository.Updates(ctx.Tx, req.ConversationID, map[string]any{
 			"current_assignee_id": req.AssigneeID,
+			"current_team_id":     targetProfile.TeamID,
 			"status":              enums.IMConversationStatusActive,
 			"update_user_id":      operator.UserID,
 			"update_user_name":    operator.Username,
@@ -229,11 +266,12 @@ func (s *conversationService) AssignConversation(req request.AssignConversationR
 			return err
 		}
 		if err := ConversationEventLogService.CreateEvent(ctx, req.ConversationID, enums.IMEventTypeAssign, enums.IMSenderTypeAgent, operator.UserID, "会话已分配", s.buildEventPayload(map[string]any{
-			"fromStatus":     conversation.Status,
-			"toStatus":       enums.IMConversationStatusActive,
-			"fromAssigneeId": conversation.CurrentAssigneeID,
-			"toAssigneeId":   req.AssigneeID,
-			"reason":         strings.TrimSpace(req.Reason),
+			"from_status":      conversation.Status,
+			"to_status":        enums.IMConversationStatusActive,
+			"from_assignee_id": conversation.CurrentAssigneeID,
+			"to_assignee_id":   req.AssigneeID,
+			"to_team_id":       targetProfile.TeamID,
+			"reason":           strings.TrimSpace(req.Reason),
 		})); err != nil {
 			return err
 		}
@@ -252,6 +290,7 @@ func (s *conversationService) AssignConversation(req request.AssignConversationR
 	if conversation := s.Get(req.ConversationID); conversation != nil {
 		WsService.PublishConversationChanged(conversation, enums.IMRealtimeEventConversationAssigned)
 	}
+	ConversationQueueService.PublishPoolUpdates(previousTeamID)
 	eventbus.PublishAsync(context.Background(), assignedEvent)
 	return nil
 }
@@ -272,15 +311,25 @@ func (s *conversationService) AutoAssignConversation(conversationID int64, opera
 		return errorsx.InvalidParamI18n("error.e0190")
 	}
 
-	aiAgent := AIAgentService.Get(conversation.AIAgentID)
-	if aiAgent == nil || aiAgent.Status != enums.StatusOk {
-		return errorsx.InvalidParamI18n("error.e0003")
+	if conversation.AIAgentID > 0 {
+		aiAgent := AIAgentService.Get(conversation.AIAgentID)
+		if aiAgent == nil || aiAgent.Status != enums.StatusOk {
+			return errorsx.InvalidParamI18n("error.e0003")
+		}
+		result, err := ConversationHumanDispatchService.DispatchPendingConversation(conversationID, *aiAgent)
+		if err != nil {
+			return err
+		}
+		if result == nil || result.Decision == HandoffDecisionOffHours {
+			return errorsx.InvalidParamI18n("error.e0194")
+		}
+		return nil
 	}
-	result, err := ConversationHumanDispatchService.DispatchPendingConversation(conversationID, *aiAgent)
+	result, err := ConversationDispatchService.DispatchConversation(conversationID)
 	if err != nil {
 		return err
 	}
-	if result == nil || result.Decision == HandoffDecisionOffHours {
+	if result == nil {
 		return errorsx.InvalidParamI18n("error.e0194")
 	}
 	return nil
@@ -332,11 +381,11 @@ func (s *conversationService) TransferConversation(conversationID, toUserID int6
 			return err
 		}
 		if err := ConversationEventLogService.CreateEvent(ctx, conversationID, enums.IMEventTypeTransfer, enums.IMSenderTypeAgent, operator.UserID, "会话已转接", s.buildEventPayload(map[string]any{
-			"fromStatus":     conversation.Status,
-			"toStatus":       enums.IMConversationStatusActive,
-			"fromAssigneeId": conversation.CurrentAssigneeID,
-			"toAssigneeId":   toUserID,
-			"reason":         strings.TrimSpace(reason),
+			"from_status":      conversation.Status,
+			"to_status":        enums.IMConversationStatusActive,
+			"from_assignee_id": conversation.CurrentAssigneeID,
+			"to_assignee_id":   toUserID,
+			"reason":           strings.TrimSpace(reason),
 		})); err != nil {
 			return err
 		}
@@ -416,6 +465,8 @@ func (s *conversationService) CloseCustomerConversation(conversationID int64, ex
 }
 
 func (s *conversationService) closeConversation(conversationID int64, senderType enums.IMSenderType, closeReason string, operator *dto.AuthPrincipal) error {
+	var queuedTeamID int64
+	var wasQueued bool
 	if err := sqls.WithTransaction(func(ctx *sqls.TxContext) error {
 		conversation := repositories.ConversationRepository.Get(ctx.Tx, conversationID)
 		if conversation == nil {
@@ -429,6 +480,8 @@ func (s *conversationService) closeConversation(conversationID int64, senderType
 			conversation.Status != enums.IMConversationStatusActive {
 			return errorsx.InvalidParamI18n("error.e0197")
 		}
+		wasQueued = conversation.Status == enums.IMConversationStatusPending && conversation.CurrentAssigneeID == 0
+		queuedTeamID = conversation.CurrentTeamID
 		var (
 			now          = time.Now()
 			eventDesc    = "会话已关闭"
@@ -466,11 +519,11 @@ func (s *conversationService) closeConversation(conversationID int64, senderType
 			return err
 		}
 		return ConversationEventLogService.CreateEvent(ctx, conversationID, enums.IMEventTypeClose, senderType, operatorID, eventDesc, s.buildEventPayload(map[string]any{
-			"fromStatus":     conversation.Status,
-			"toStatus":       enums.IMConversationStatusClosed,
-			"fromAssigneeId": conversation.CurrentAssigneeID,
-			"toAssigneeId":   conversation.CurrentAssigneeID,
-			"closeReason":    closeReason,
+			"from_status":      conversation.Status,
+			"to_status":        enums.IMConversationStatusClosed,
+			"from_assignee_id": conversation.CurrentAssigneeID,
+			"to_assignee_id":   conversation.CurrentAssigneeID,
+			"close_reason":     closeReason,
 		}))
 	}); err != nil {
 		return err
@@ -478,6 +531,9 @@ func (s *conversationService) closeConversation(conversationID int64, senderType
 	if conversation := s.Get(conversationID); conversation != nil {
 		WsService.PublishConversationChanged(conversation, enums.IMRealtimeEventConversationClosed)
 	}
+	if wasQueued {
+		ConversationQueueService.PublishPoolUpdates(queuedTeamID)
+	}
 	return nil
 }
 
@@ -681,14 +737,11 @@ func (s *conversationService) IsCustomerConversationOwner(conversation *models.C
 		return false
 	}
 	extID := strings.TrimSpace(externalUser.ExternalID)
-	if extID == "" || strings.TrimSpace(string(externalUser.ExternalSource)) == "" || conversation.CustomerID <= 0 {
+	if extID == "" || strings.TrimSpace(string(externalUser.ExternalSource)) == "" {
 		return false
 	}
-	identity := repositories.CustomerIdentityRepository.GetBy(sqls.DB(), externalUser.ExternalSource, extID)
-	if identity == nil {
-		return false
-	}
-	return identity.CustomerID == conversation.CustomerID
+	return conversation.CustomerType == externalCustomerType(externalUser) &&
+		strings.TrimSpace(conversation.CustomerExternalID) == extID
 }
 
 func (s *conversationService) BuildConversationSummary(conversation *models.Conversation) string {
@@ -701,14 +754,11 @@ func (s *conversationService) BuildConversationSummary(conversation *models.Conv
 	return strings.TrimSpace(conversation.CustomerName)
 }
 
-func (s *conversationService) getCustomerName(db *gorm.DB, customerID int64) string {
-	if customerID <= 0 {
-		return ""
+func externalCustomerType(externalUser openidentity.ExternalUser) string {
+	if externalUser.SubjectType != "" {
+		return string(externalUser.SubjectType)
 	}
-	if customer := repositories.CustomerRepository.Get(db, customerID); customer != nil {
-		return strings.TrimSpace(customer.Name)
-	}
-	return ""
+	return string(externalUser.ExternalSource)
 }
 
 func (s *conversationService) canCloseConversation(conversation *models.Conversation, operator *dto.AuthPrincipal) bool {
@@ -751,101 +801,23 @@ func (s *conversationService) buildEventPayload(payload map[string]any) string {
 	return string(data)
 }
 
-// LinkConversationCustomer 将会话绑定到指定客户。
-func (s *conversationService) LinkConversationCustomer(conversationID, customerID int64, operator *dto.AuthPrincipal) error {
-	if operator == nil {
-		return errorsx.UnauthorizedI18n("error.auth.expired")
-	}
-	if conversationID <= 0 || customerID <= 0 {
-		return errorsx.InvalidParamI18n("error.e0133")
-	}
-	cust := CustomerService.Get(customerID)
-	if cust == nil || cust.Status == enums.StatusDeleted {
-		return errorsx.InvalidParamI18n("error.e0155")
-	}
-	conv := s.Get(conversationID)
-	if conv == nil {
-		return errorsx.InvalidParamI18n("error.e0116")
-	}
-	if conv.Status == enums.IMConversationStatusClosed {
-		return errorsx.InvalidParamI18n("error.e0183")
-	}
-	if !s.canLinkConversationCustomer(conv, operator) {
-		return errorsx.ForbiddenI18n("error.e0224")
-	}
-
-	err := sqls.WithTransaction(func(ctx *sqls.TxContext) error {
-		current := repositories.ConversationRepository.Get(ctx.Tx, conversationID)
-		if current == nil {
-			return errorsx.InvalidParamI18n("error.e0116")
-		}
-		now := time.Now()
-		return repositories.ConversationRepository.Updates(ctx.Tx, conversationID, map[string]any{
-			"customer_id":      customerID,
-			"customer_name":    strings.TrimSpace(cust.Name),
-			"update_user_id":   operator.UserID,
-			"update_user_name": operator.Username,
-			"updated_at":       now,
-		})
-	})
-	if err != nil {
-		return err
-	}
-	if updated := s.Get(conversationID); updated != nil {
-		WsService.PublishConversationChanged(updated, enums.IMRealtimeEventConversationUpdated)
-	}
-	return nil
-}
-
-func (s *conversationService) GetConversationExternalIdentity(conversation *models.Conversation) *models.CustomerIdentity {
-	if conversation == nil || conversation.CustomerID <= 0 {
+func (s *conversationService) GetConversationExternalIdentity(conversation *models.Conversation) *openidentity.ExternalUser {
+	if conversation == nil || strings.TrimSpace(conversation.CustomerExternalID) == "" {
 		return nil
 	}
-	identities := repositories.CustomerIdentityRepository.FindByCustomerID(sqls.DB(), conversation.CustomerID)
-	if len(identities) == 0 {
-		return nil
+	external := &openidentity.ExternalUser{
+		ExternalID:   strings.TrimSpace(conversation.CustomerExternalID),
+		ExternalName: strings.TrimSpace(conversation.CustomerName),
+		SubjectID:    conversation.CustomerID,
 	}
-	if channel := ChannelService.Get(conversation.ChannelID); channel != nil {
-		expected := externalSourceForChannelType(channel.ChannelType)
-		if strings.TrimSpace(string(expected)) != "" {
-			for i := range identities {
-				if identities[i].ExternalSource == expected {
-					return &identities[i]
-				}
-			}
-		}
-	}
-	return &identities[0]
-}
-
-func externalSourceForChannelType(channelType string) enums.ExternalSource {
-	switch strings.TrimSpace(channelType) {
-	case enums.ChannelTypeWxWorkKF:
-		return enums.ExternalSourceWxWorkKF
-	case enums.ChannelTypeWeb:
-		return enums.ExternalSourceGuest
+	switch conversation.CustomerType {
+	case string(identity.SubjectCard), string(identity.SubjectDevice), string(identity.SubjectMallUser):
+		external.ExternalSource = enums.ExternalSourceUser
+		external.SubjectType = identity.SubjectType(conversation.CustomerType)
 	default:
-		return ""
-	}
-}
-
-func (s *conversationService) canLinkConversationCustomer(conv *models.Conversation, operator *dto.AuthPrincipal) bool {
-	if conv == nil || operator == nil {
-		return false
-	}
-	if s.isAdmin(operator) {
-		return true
-	}
-	switch conv.Status {
-	case enums.IMConversationStatusAIServing:
-		return true
-	case enums.IMConversationStatusPending:
-		return true
-	case enums.IMConversationStatusActive:
-		return conv.CurrentAssigneeID == 0 || conv.CurrentAssigneeID == operator.UserID
-	default:
-		return false
+		external.ExternalSource = enums.ExternalSource(conversation.CustomerType)
 	}
+	return external
 }
 
 func (s *conversationService) resolveInitialStatus(serviceMode enums.IMConversationServiceMode) enums.IMConversationStatus {