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/pkg/enums/im.go

@@ -240,20 +240,21 @@ func GetAIAgentFallbackModeLabel(mode AIAgentFallbackMode) string {
 }
 
 const (
-	IMRealtimeEventConnected               = "connected"
-	IMRealtimeEventPong                    = "pong"
-	IMRealtimeEventSubscribed              = "subscribed"
-	IMRealtimeEventUnsubscribed            = "unsubscribed"
-	IMRealtimeEventResyncRequired          = "resyncRequired"
-	IMRealtimeEventMessageCreated          = "message.created"
-	IMRealtimeEventMessageRecalled         = "message.recalled"
-	IMRealtimeEventConversationCreated     = "conversation.created"
-	IMRealtimeEventConversationUpdated     = "conversation.updated"
-	IMRealtimeEventConversationAssigned    = "conversation.assigned"
-	IMRealtimeEventConversationTransferred = "conversation.transferred"
-	IMRealtimeEventConversationClosed      = "conversation.closed"
-	IMRealtimeEventConversationRead        = "conversation.read"
-	IMRealtimeEventNotificationCreated     = "notification.created"
+	IMRealtimeEventConnected                = "connected"
+	IMRealtimeEventPong                     = "pong"
+	IMRealtimeEventSubscribed               = "subscribed"
+	IMRealtimeEventUnsubscribed             = "unsubscribed"
+	IMRealtimeEventResyncRequired           = "resyncRequired"
+	IMRealtimeEventMessageCreated           = "message.created"
+	IMRealtimeEventMessageRecalled          = "message.recalled"
+	IMRealtimeEventConversationCreated      = "conversation.created"
+	IMRealtimeEventConversationUpdated      = "conversation.updated"
+	IMRealtimeEventConversationAssigned     = "conversation.assigned"
+	IMRealtimeEventConversationTransferred  = "conversation.transferred"
+	IMRealtimeEventConversationClosed       = "conversation.closed"
+	IMRealtimeEventConversationRead         = "conversation.read"
+	IMRealtimeEventConversationQueueUpdated = "conversation.queue_updated"
+	IMRealtimeEventNotificationCreated      = "notification.created"
 )
 
 const (