feat: 集成健康数据功能

- 在项目中引入 react-native-health 库以获取健康数据
- 在 Explore 页面中添加步数和能量消耗的显示
- 实现页面聚焦时自动拉取今日健康数据
- 更新 iOS 权限设置以支持健康数据访问
- 添加健康数据相关的工具函数以简化数据获取

app/(tabs)/explore.tsx

@@ -2,8 +2,10 @@ import { ProgressBar } from '@/components/ProgressBar';
 import { Colors } from '@/constants/Colors';
 import { getTabBarBottomPadding } from '@/constants/TabBar';
 import { getMonthDaysZh, getMonthTitleZh, getTodayIndexInMonth } from '@/utils/date';
+import { ensureHealthPermissions, fetchTodayHealthData } from '@/utils/health';
 import { Ionicons } from '@expo/vector-icons';
 import { useBottomTabBarHeight } from '@react-navigation/bottom-tabs';
+import { useFocusEffect } from '@react-navigation/native';
 import React, { useEffect, useMemo, useRef, useState } from 'react';
 import {
   SafeAreaView,
@@ -46,6 +48,30 @@ export default function ExploreScreen() {
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [scrollWidth]);
 
+  // HealthKit: 每次页面聚焦都拉取今日数据
+  const [stepCount, setStepCount] = useState<number | null>(null);
+  const [activeCalories, setActiveCalories] = useState<number | null>(null);
+
+  useFocusEffect(
+    React.useCallback(() => {
+      let isActive = true;
+      const run = async () => {
+        console.log('HealthKit init start');
+        const ok = await ensureHealthPermissions();
+        if (!ok) return;
+        const data = await fetchTodayHealthData();
+        if (!isActive) return;
+        setStepCount(data.steps);
+        setActiveCalories(Math.round(data.activeEnergyBurned));
+      };
+      run();
+      return () => {
+        isActive = false;
+      };
+    }, [])
+  );
+
+
   return (
     <View style={styles.container}>
       <SafeAreaView style={styles.safeArea}>
@@ -100,15 +126,17 @@ export default function ExploreScreen() {
             <View style={styles.metricsRight}>
               <View style={[styles.metricsRightCard, styles.caloriesCard, { minHeight: 88 }]}>
                 <Text style={styles.cardTitleSecondary}>消耗卡路里</Text>
-                <Text style={styles.caloriesValue}>645 千卡</Text>
+                <Text style={styles.caloriesValue}>
+                  {activeCalories != null ? `${activeCalories} 千卡` : '——'}
+                </Text>
               </View>
               <View style={[styles.metricsRightCard, styles.stepsCard, { minHeight: 88 }]}>
                 <View style={styles.cardHeaderRow}>
                   <View style={styles.iconSquare}><Ionicons name="footsteps-outline" size={18} color="#192126" /></View>
                   <Text style={styles.cardTitle}>步数</Text>
                 </View>
-                <Text style={styles.stepsValue}>999/2000</Text>
-                <ProgressBar progress={0.5} height={12} trackColor="#FFEBCB" fillColor="#FFC365" />
+                <Text style={styles.stepsValue}>{stepCount != null ? `${stepCount}/2000` : '——/2000'}</Text>
+                <ProgressBar progress={Math.min(1, Math.max(0, (stepCount ?? 0) / 2000))} height={12} trackColor="#FFEBCB" fillColor="#FFC365" />
               </View>
             </View>
           </View>