feat: 添加标靶数量上限提示，限制最多可绘制5个标靶

client/src/sections/wuyuanbiaoba/components/CameraView.jsx

@@ -1,5 +1,6 @@
 import React, { useRef, useEffect, useState, useCallback } from "react";
 import { useWebSocket } from "../actions/websocket.jsx";
+import { message } from "antd";
 import { useTargetStorage } from "../hooks/useTargetStorage.js";
 const CameraView = ({
    selectedTargetId,
@@ -166,6 +167,8 @@ const CameraView = ({
                setStartPos({ x: mouseX, y: mouseY });
                setDrawing(true);
                setCurrentDrawingRect(null);
+            }else{
+               message.warning("已达到标靶数量上限（5个）！");
             }
          }
          e.preventDefault();