fix build sv

server/internal/websocket/websocket.go

@@ -381,7 +381,7 @@ func (h *WsHub) Unsubscribe(teacherAddr string, studentID int64) {
 	}
 }
 
-func (h *WsHub) RelayFrame(studentID int64, event string, data map[string]any) {
+func (h *WsHub) RelayFrameRaw(studentID int64, event string, rawImageBuffer json.RawMessage) {
 	h.mu.RLock()
 	teachersList, exists := h.subscribers[studentID]
 	if !exists || len(teachersList) == 0 {
@@ -397,13 +397,20 @@ func (h *WsHub) RelayFrame(studentID int64, event string, data map[string]any) {
 		relayEvent = "teacher:webcam-stream-frame"
 	}
 
-	msg := SocketMsg{
-		Event: relayEvent,
-		Data: map[string]any{
-			"studentId":   studentID,
-			"imageBuffer": data["imageBuffer"],
-		},
+	type RelayFrameRawMsg struct {
+		Event string `json:"event"`
+		Data  struct {
+			StudentID   int64           `json:"studentId"`
+			ImageBuffer json.RawMessage `json:"imageBuffer"`
+		} `json:"data"`
 	}
+
+	msg := RelayFrameRawMsg{
+		Event: relayEvent,
+	}
+	msg.Data.StudentID = studentID
+	msg.Data.ImageBuffer = rawImageBuffer
+
 	msgBytes, err := json.Marshal(msg)
 	if err != nil {
 		return
@@ -497,6 +504,26 @@ func WebSocketHandler(db *gorm.DB) func(*websocket.Conn) {
 			}
 			_ = c.SetReadDeadline(time.Now().Add(wsPongWait))
 
+			type EventOnlyMsg struct {
+				Event string `json:"event"`
+			}
+			var eventMsg EventOnlyMsg
+			if err := json.Unmarshal(msgBytes, &eventMsg); err != nil {
+				continue
+			}
+
+			if eventMsg.Event == "screenshot_stream_frame" || eventMsg.Event == "webcam_stream_frame" {
+				var frameMsg struct {
+					Data struct {
+						ImageBuffer json.RawMessage `json:"imageBuffer"`
+					} `json:"data"`
+				}
+				if err := json.Unmarshal(msgBytes, &frameMsg); err == nil {
+					Hub.RelayFrameRaw(client.StudentID, eventMsg.Event, frameMsg.Data.ImageBuffer)
+				}
+				continue
+			}
+
 			var msg SocketMsg
 			if err := json.Unmarshal(msgBytes, &msg); err != nil {
 				continue
@@ -506,9 +533,6 @@ func WebSocketHandler(db *gorm.DB) func(*websocket.Conn) {
 			case "client:ping":
 				_ = client.WriteJSON(SocketMsg{Event: "client:pong", Data: map[string]any{"t": time.Now().UnixMilli()}})
 
-			case "screenshot_stream_frame", "webcam_stream_frame":
-				Hub.RelayFrame(client.StudentID, msg.Event, msg.Data)
-
 			case "teacher:subscribe":
 				if client.Role == "teacher" {
 					if sIDVal, ok := msg.Data["studentId"]; ok {