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/builders/conversation_builder.go

@@ -23,7 +23,9 @@ func BuildConversationWithLocale(item *models.Conversation, locale string) respo
 		ID:                        item.ID,
 		AIAgentID:                 item.AIAgentID,
 		ChannelID:                 item.ChannelID,
+		CustomerType:              item.CustomerType,
 		CustomerID:                item.CustomerID,
+		CustomerExternalID:        item.CustomerExternalID,
 		CustomerName:              item.CustomerName,
 		Status:                    item.Status,
 		ServiceMode:               item.ServiceMode,
@@ -47,6 +49,18 @@ func BuildConversationWithLocale(item *models.Conversation, locale string) respo
 	if identity := services.ConversationService.GetConversationExternalIdentity(item); identity != nil {
 		ret.CustomerOnline = services.WsService.IsGuestOnline(identity.ExternalID)
 	}
+	queueSnapshot := services.ConversationQueueService.GetSnapshot(item)
+	if queueSnapshot.Queued {
+		ret.QueueEnteredAt = utils.FormatTimePtr(queueSnapshot.EnteredAt)
+		ret.QueuePosition = queueSnapshot.Position
+		ret.QueueAheadCount = queueSnapshot.AheadCount
+		ret.QueueWaitingCount = queueSnapshot.WaitingCount
+		ret.QueueWaitSeconds = queueSnapshot.WaitSeconds
+		ret.QueueEstimatedWaitSeconds = queueSnapshot.EstimatedWaitSeconds
+		ret.QueueEscalationLevel = queueSnapshot.EscalationLevel
+		ret.EffectivePriority = queueSnapshot.EffectivePriority
+		ret.QueueServiceOnline = queueSnapshot.ServiceOnline
+	}
 	if item.CurrentAssigneeID > 0 {
 		if user := services.UserService.Get(item.CurrentAssigneeID); user != nil {
 			ret.CurrentAssigneeName = user.Nickname
@@ -120,11 +134,11 @@ func BuildMessagesWithLocale(list []models.Message, locale string) []response.Me
 		return nil
 	}
 	agentReadState, customerReadState := services.ConversationReadStateService.GetConversationReadStates(list[0].ConversationID)
-	aiSenderNames, userSenderNames := collectMessageSenderNameMaps(list)
+	aiSenders, userSenderNames := collectMessageSenderMaps(list)
 	agentProfiles := collectAgentProfilesByMessages(list)
 	ret := make([]response.MessageResponse, 0, len(list))
 	for i := range list {
-		ret = append(ret, BuildMessageWithReadStatesAndLocale(&list[i], agentReadState, customerReadState, aiSenderNames, userSenderNames, agentProfiles, locale))
+		ret = append(ret, BuildMessageWithReadStatesAndLocale(&list[i], agentReadState, customerReadState, aiSenders, userSenderNames, agentProfiles, locale))
 	}
 	return ret
 }
@@ -138,17 +152,16 @@ func BuildMessageWithLocale(item *models.Message, locale string) response.Messag
 	return BuildMessageWithReadStatesAndLocale(item, agentReadState, customerReadState, nil, nil, nil, locale)
 }
 
-func BuildMessageWithReadStates(item *models.Message, agentReadState, customerReadState *models.ConversationReadState, aiSenderNames, userSenderNames map[int64]string, agentProfiles map[int64]*models.AgentProfile) response.MessageResponse {
-	return BuildMessageWithReadStatesAndLocale(item, agentReadState, customerReadState, aiSenderNames, userSenderNames, agentProfiles, i18nx.DefaultLocale)
+func BuildMessageWithReadStates(item *models.Message, agentReadState, customerReadState *models.ConversationReadState, aiSenders map[int64]*models.AIAgent, userSenderNames map[int64]string, agentProfiles map[int64]*models.AgentProfile) response.MessageResponse {
+	return BuildMessageWithReadStatesAndLocale(item, agentReadState, customerReadState, aiSenders, userSenderNames, agentProfiles, i18nx.DefaultLocale)
 }
 
-func BuildMessageWithReadStatesAndLocale(item *models.Message, agentReadState, customerReadState *models.ConversationReadState, aiSenderNames, userSenderNames map[int64]string, agentProfiles map[int64]*models.AgentProfile, locale string) response.MessageResponse {
+func BuildMessageWithReadStatesAndLocale(item *models.Message, agentReadState, customerReadState *models.ConversationReadState, aiSenders map[int64]*models.AIAgent, userSenderNames map[int64]string, agentProfiles map[int64]*models.AgentProfile, locale string) response.MessageResponse {
 	content, payload := utils.BuildRenderableMessage(item)
 	ret := response.MessageResponse{
 		ID:              item.ID,
 		ConversationID:  item.ConversationID,
 		RequestID:       item.RequestID,
-		WorkflowRunID:   item.WorkflowRunID,
 		ClientMsgID:     item.ClientMsgID,
 		SenderType:      item.SenderType,
 		SenderID:        item.SenderID,
@@ -168,10 +181,13 @@ func BuildMessageWithReadStatesAndLocale(item *models.Message, agentReadState, c
 	}
 	if item.SenderID > 0 {
 		if item.SenderType == enums.IMSenderTypeAI {
-			if aiSenderNames != nil {
-				ret.SenderName = aiSenderNames[item.SenderID]
-			} else if aiAgent := services.AIAgentService.Get(item.SenderID); aiAgent != nil {
+			aiAgent := aiSenders[item.SenderID]
+			if aiAgent == nil {
+				aiAgent = services.AIAgentService.Get(item.SenderID)
+			}
+			if aiAgent != nil {
 				ret.SenderName = aiAgent.Name
+				ret.SenderAvatar = strings.TrimSpace(aiAgent.Avatar)
 			}
 		} else if item.SenderType == enums.IMSenderTypeAgent {
 			profile := agentProfiles[item.SenderID]
@@ -240,8 +256,8 @@ func collectAgentProfilesByMessages(list []models.Message) map[int64]*models.Age
 	return out
 }
 
-func collectMessageSenderNameMaps(list []models.Message) (aiNames map[int64]string, userNames map[int64]string) {
-	aiNames = make(map[int64]string)
+func collectMessageSenderMaps(list []models.Message) (aiSenders map[int64]*models.AIAgent, userNames map[int64]string) {
+	aiSenders = make(map[int64]*models.AIAgent)
 	userNames = make(map[int64]string)
 	var aiIDs, userIDs []int64
 	seenAI := make(map[int64]struct{})
@@ -266,7 +282,8 @@ func collectMessageSenderNameMaps(list []models.Message) (aiNames map[int64]stri
 		userIDs = append(userIDs, m.SenderID)
 	}
 	for _, a := range services.AIAgentService.FindByIds(aiIDs) {
-		aiNames[a.ID] = a.Name
+		agent := a
+		aiSenders[a.ID] = &agent
 	}
 	for _, u := range services.UserService.FindByIds(userIDs) {
 		name := u.Nickname
@@ -275,7 +292,7 @@ func collectMessageSenderNameMaps(list []models.Message) (aiNames map[int64]stri
 		}
 		userNames[u.ID] = name
 	}
-	return aiNames, userNames
+	return aiSenders, userNames
 }
 
 func isMessageRead(item *models.Message, state *models.ConversationReadState) bool {