feat: 移除目标管理演示页面并优化相关组件

- 删除目标管理演示页面的代码，简化项目结构
- 更新底部导航，移除目标管理演示页面的路由
- 调整相关组件的样式和逻辑，确保界面一致性
- 优化颜色常量的使用，提升视觉效果

components/statistic/HeartRateCard.tsx

@@ -1,29 +1,19 @@
 import { Ionicons } from '@expo/vector-icons';
-import React, { useEffect, useState } from 'react';
+import React from 'react';
 import { StyleSheet } from 'react-native';
-import HealthDataService from '../../services/healthData';
 import HealthDataCard from './HealthDataCard';
 
 interface HeartRateCardProps {
   resetToken: number;
   style?: object;
+  heartRate?: number | null;
 }
 
 const HeartRateCard: React.FC<HeartRateCardProps> = ({
   resetToken,
-  style
+  style,
+  heartRate
 }) => {
-  const [heartRate, setHeartRate] = useState<number | null>(null);
-
-  useEffect(() => {
-    const fetchHeartRate = async () => {
-      const data = await HealthDataService.getHeartRate();
-      setHeartRate(data);
-    };
-
-    fetchHeartRate();
-  }, [resetToken]);
-
   const heartIcon = (
     <Ionicons name="heart" size={24} color="#EF4444" />
   );
@@ -31,7 +21,7 @@ const HeartRateCard: React.FC<HeartRateCardProps> = ({
   return (
     <HealthDataCard
       title="心率"
-      value={heartRate !== null ? heartRate.toString() : '--'}
+      value={heartRate !== null && heartRate !== undefined ? Math.round(heartRate).toString() : '--'}
       unit="bpm"
       icon={heartIcon}
       style={style}