feat(health): 新增手腕温度监测和经期双向同步功能

新增手腕温度健康数据追踪，支持Apple Watch睡眠手腕温度数据展示和30天历史趋势分析
实现经期数据与HealthKit的完整双向同步，支持读取、写入和删除经期记录
优化经期预测算法，基于历史数据计算更准确的周期和排卵日预测
重构经期UI组件为模块化结构，提升代码可维护性
添加完整的中英文国际化支持，覆盖所有新增功能界面

components/menstrual-cycle/Legend.tsx

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+import React from 'react';
+import { StyleSheet, Text, View } from 'react-native';
+import { STATUS_COLORS } from './constants';
+import { LegendItem } from './types';
+
+const LEGEND_ITEMS: LegendItem[] = [
+  { label: '经期', key: 'period' },
+  { label: '预测经期', key: 'predicted-period' },
+  { label: '排卵期', key: 'fertile' },
+  { label: '排卵日', key: 'ovulation-day' },
+];
+
+export const Legend: React.FC = () => {
+  return (
+    <View style={styles.legendRow}>
+      {LEGEND_ITEMS.map((item) => (
+        <View key={item.key} style={styles.legendItem}>
+          <View
+            style={[
+              styles.legendDot,
+              { backgroundColor: STATUS_COLORS[item.key].bg },
+              item.key === 'ovulation-day' && styles.legendDotRing,
+            ]}
+          />
+          <Text style={styles.legendLabel}>{item.label}</Text>
+        </View>
+      ))}
+    </View>
+  );
+};
+
+const styles = StyleSheet.create({
+  legendRow: {
+    flexDirection: 'row',
+    flexWrap: 'wrap',
+    gap: 12,
+    marginBottom: 12,
+    paddingHorizontal: 4,
+  },
+  legendItem: {
+    flexDirection: 'row',
+    alignItems: 'center',
+  },
+  legendDot: {
+    width: 16,
+    height: 16,
+    borderRadius: 8,
+    marginRight: 6,
+  },
+  legendDotRing: {
+    borderWidth: 2,
+    borderColor: '#fff',
+  },
+  legendLabel: {
+    fontSize: 13,
+    color: '#111827',
+    fontFamily: 'AliRegular',
+  },
+});