feat(call): add media type support to call invite functionality

- Updated the WSHandler to include a media type field in the call invite request, allowing differentiation between voice and video calls.
- Modified the CallService interface and implementation to accept the media type parameter during call invitations, enhancing call handling capabilities.

internal/handler/ws_handler.go

@@ -450,6 +450,7 @@ func (h *WSHandler) handleCallInvite(ctx context.Context, client *ws.Client, pay
 	var req struct {
 		CalleeID       string `json:"callee_id"`
 		ConversationID string `json:"conversation_id"`
+		MediaType      string `json:"call_type"` // voice 或 video
 	}
 	if err := json.Unmarshal(payload, &req); err != nil {
 		h.wsHub.SendError(client, "parse_error", "invalid call_invite format")
@@ -460,7 +461,13 @@ func (h *WSHandler) handleCallInvite(ctx context.Context, client *ws.Client, pay
 		return
 	}
 
-	call, err := h.callService.Invite(ctx, client.UserID, req.CalleeID, req.ConversationID)
+	// 前端传的 call_type 是 voice/video，默认为 voice
+	mediaType := req.MediaType
+	if mediaType != "video" {
+		mediaType = "voice"
+	}
+
+	call, err := h.callService.Invite(ctx, client.UserID, req.CalleeID, req.ConversationID, mediaType)
 	if err != nil {
 		zap.L().Warn("Failed to invite call",
 			zap.String("caller_id", client.UserID),

internal/service/call_service.go

@@ -33,7 +33,7 @@ const (
 
 // CallService 通话服务接口
 type CallService interface {
-	Invite(ctx context.Context, callerID, calleeID, conversationID string) (*model.CallSession, error)
+	Invite(ctx context.Context, callerID, calleeID, conversationID, mediaType string) (*model.CallSession, error)
 	Accept(ctx context.Context, callID, userID string) (*model.CallSession, error)
 	Reject(ctx context.Context, callID, userID string) error
 	Busy(ctx context.Context, callID, userID string) error
@@ -72,7 +72,7 @@ func NewCallService(
 	return svc
 }
 
-func (s *callService) Invite(ctx context.Context, callerID, calleeID, conversationID string) (*model.CallSession, error) {
+func (s *callService) Invite(ctx context.Context, callerID, calleeID, conversationID, mediaType string) (*model.CallSession, error) {
 	// === Telegram: 检查被叫方是否在线 ===
 	if !s.hub.HasClients(calleeID) {
 		return nil, ErrCalleeOffline
@@ -113,6 +113,7 @@ func (s *callService) Invite(ctx context.Context, callerID, calleeID, conversati
 		"conversation_id": conversationID,
 		"caller_id":       callerID,
 		"call_type":       call.CallType,
+		"media_type":      mediaType,
 		"created_at":      now.UnixMilli(),
 		"lifetime":        CallLifetimeMs,
 		"ice_servers":     s.config.WebRTC.ICEServers,