refactor(sleep): 重构睡眠数据获取逻辑，移除冗余代码并优化组件结构

- 从 healthSlice 和 health.ts 中移除 sleepDuration 字段及相关获取逻辑
- 将 SleepCard 改为按需异步获取睡眠数据，支持传入指定日期
- 睡眠详情页改为通过路由参数接收日期，支持查看历史记录
- 移除 statistics 页面对 sleepDuration 的直接依赖，统一由 SleepCard 管理
- 删除未使用的 SleepStageChart 组件，简化页面结构

components/statistic/SleepCard.tsx

@@ -1,22 +1,40 @@
-import React from 'react';
-import { StyleSheet, Text, View, TouchableOpacity } from 'react-native';
+import { fetchCompleteSleepData, formatSleepTime } from '@/utils/sleepHealthKit';
+import React, { useEffect, useState } from 'react';
+import { StyleSheet, Text, TouchableOpacity, View } from 'react-native';
 
 interface SleepCardProps {
-  sleepDuration?: number | null;
+  selectedDate?: Date;
   style?: object;
   onPress?: () => void;
 }
 
 const SleepCard: React.FC<SleepCardProps> = ({
-  sleepDuration,
+  selectedDate,
   style,
   onPress
 }) => {
-  const formatSleepDuration = (duration: number): string => {
-    const hours = Math.floor(duration / 60);
-    const minutes = Math.floor(duration % 60);
-    return `${hours}小时${minutes}分钟`;
-  };
+  const [sleepDuration, setSleepDuration] = useState<number | null>(null);
+  const [loading, setLoading] = useState(false);
+
+  // 获取睡眠数据
+  useEffect(() => {
+    const loadSleepData = async () => {
+      if (!selectedDate) return;
+
+      try {
+        setLoading(true);
+        const data = await fetchCompleteSleepData(selectedDate);
+        setSleepDuration(data?.totalSleepTime || null);
+      } catch (error) {
+        console.error('SleepCard: 获取睡眠数据失败:', error);
+        setSleepDuration(null);
+      } finally {
+        setLoading(false);
+      }
+    };
+
+    loadSleepData();
+  }, [selectedDate]);
 
   const CardContent = (
     <View style={[styles.container, style]}>
@@ -24,7 +42,7 @@ const SleepCard: React.FC<SleepCardProps> = ({
         <Text style={styles.cardTitle}>睡眠</Text>
       </View>
       <Text style={styles.sleepValue}>
-        {sleepDuration != null ? formatSleepDuration(sleepDuration) : '——'}
+        {loading ? '加载中...' : (sleepDuration != null ? formatSleepTime(sleepDuration) : '--')}
       </Text>
     </View>
   );