feat(call): integrate LiveKit for voice and video calling

Replace the manual WebRTC signaling implementation with LiveKit SFU. This includes:
- Adding LiveKit service, handler, and configuration.
- Updating Docker Compose to include LiveKit server, Redis, and PostgreSQL.
- Refactoring `CallService` and `WSHandler` to support LiveKit room readiness instead of raw SDP/ICE relaying.
- Adding new API endpoints for LiveKit token generation and webhooks.
- Removing deprecated WebRTC configuration and manual signaling DTOs.

internal/router/router.go

@@ -39,6 +39,7 @@ type RouterDeps struct {
 	QRCodeHandler            *handler.QRCodeHandler
 	MaterialHandler          *handler.MaterialHandler
 	CallHandler              *handler.CallHandler
+	LiveKitHandler           *handler.LiveKitHandler
 	ReportHandler            *handler.ReportHandler
 	AdminReportHandler       *handler.AdminReportHandler
 	VerificationHandler      *handler.VerificationHandler
@@ -83,6 +84,7 @@ type Router struct {
 	qrcodeHandler            *handler.QRCodeHandler
 	materialHandler          *handler.MaterialHandler
 	callHandler              *handler.CallHandler
+	liveKitHandler           *handler.LiveKitHandler
 	reportHandler            *handler.ReportHandler
 	adminReportHandler       *handler.AdminReportHandler
 	verificationHandler      *handler.VerificationHandler
@@ -130,6 +132,7 @@ func New(deps RouterDeps) *Router {
 		qrcodeHandler:            deps.QRCodeHandler,
 		materialHandler:          deps.MaterialHandler,
 		callHandler:              deps.CallHandler,
+			liveKitHandler:           deps.LiveKitHandler,
 		reportHandler:            deps.ReportHandler,
 		adminReportHandler:       deps.AdminReportHandler,
 		verificationHandler:      deps.VerificationHandler,
@@ -462,10 +465,20 @@ func (r *Router) setupRoutes() {
 			calls.Use(authMiddleware)
 			{
 				calls.GET("/history", r.callHandler.GetCallHistory)
-				calls.GET("/ice-servers", r.callHandler.GetICEServers)
 			}
 		}
 
+		// LiveKit 通话路由
+		if r.liveKitHandler != nil {
+			lk := v1.Group("/calls")
+			lk.Use(authMiddleware)
+			{
+				lk.GET("/token", r.liveKitHandler.GetToken)
+			}
+			// Webhook 不需要认证（LiveKit 服务端调用）
+			v1.POST("/calls/webhook", r.liveKitHandler.HandleWebhook)
+		}
+
 		// 消息操作路由
 		messages := v1.Group("/messages")
 		messages.Use(authMiddleware)