feat(i18n): 全面实现应用核心功能模块的国际化支持

- 新增 i18n 翻译资源，覆盖睡眠、饮水、体重、锻炼、用药 AI 识别、步数、健身圆环、基础代谢及设置等核心模块
- 重构相关页面及组件（如 SleepDetail, WaterDetail, WorkoutHistory 等）使用 `useI18n` 钩子替换硬编码文本
- 升级 `utils/date` 工具库与 `DateSelector` 组件，支持基于语言环境的日期格式化与显示
- 完善登录页、注销流程及权限申请弹窗的双语提示信息
- 优化部分页面的 UI 细节与字体样式以适配多语言显示

app/weight-records.tsx

@@ -5,6 +5,7 @@ import { Colors } from '@/constants/Colors';
 import { getTabBarBottomPadding } from '@/constants/TabBar';
 import { useAppDispatch, useAppSelector } from '@/hooks/redux';
 import { useColorScheme } from '@/hooks/useColorScheme';
+import { useI18n } from '@/hooks/useI18n';
 import { useSafeAreaTop } from '@/hooks/useSafeAreaWithPadding';
 import { appStoreReviewService } from '@/services/appStoreReview';
 import { deleteWeightRecord, fetchWeightHistory, updateUserProfile, updateWeightRecord, WeightHistoryItem } from '@/store/userSlice';
@@ -24,6 +25,7 @@ import {
 } from 'react-native';
 
 export default function WeightRecordsPage() {
+  const { t } = useI18n();
   const safeAreaTop = useSafeAreaTop()
 
   const dispatch = useAppDispatch();
@@ -43,7 +45,7 @@ export default function WeightRecordsPage() {
     try {
       await dispatch(fetchWeightHistory() as any);
     } catch (error) {
-      console.error('加载体重历史失败:', error);
+      console.error(t('weightRecords.loadingHistory'), error);
     }
   }, [dispatch]);
 
@@ -92,15 +94,15 @@ export default function WeightRecordsPage() {
       await dispatch(deleteWeightRecord(id) as any);
       await loadWeightHistory();
     } catch (error) {
-      console.error('删除体重记录失败:', error);
-      Alert.alert('错误', '删除体重记录失败，请重试');
+      console.error(t('weightRecords.alerts.deleteFailed'), error);
+      Alert.alert('错误', t('weightRecords.alerts.deleteFailed'));
     }
   };
 
   const handleWeightSave = async () => {
     const weight = parseFloat(inputWeight);
     if (isNaN(weight) || weight <= 0 || weight > 500) {
-      alert('请输入有效的体重值（0-500kg）');
+      alert(t('weightRecords.alerts.invalidWeight'));
       return;
     }
 
@@ -130,8 +132,8 @@ export default function WeightRecordsPage() {
       setEditingRecord(null);
       await loadWeightHistory();
     } catch (error) {
-      console.error('保存体重失败:', error);
-      Alert.alert('错误', '保存体重失败，请重试');
+      console.error(t('weightRecords.alerts.saveFailed'), error);
+      Alert.alert('错误', t('weightRecords.alerts.saveFailed'));
     }
   };
 
@@ -190,7 +192,7 @@ export default function WeightRecordsPage() {
       />
 
       <HeaderBar
-        title="体重记录"
+        title={t('weightRecords.title')}
         right={<TouchableOpacity onPress={handleAddWeight} style={styles.addButton}>
           <Ionicons name="add" size={24} color="#192126" />
         </TouchableOpacity>}
@@ -204,27 +206,27 @@ export default function WeightRecordsPage() {
         <View style={styles.statsRow}>
           <View style={styles.statItem}>
             <Text style={styles.statValue}>{totalWeightLoss.toFixed(1)}kg</Text>
-            <Text style={styles.statLabel}>累计减重</Text>
+            <Text style={styles.statLabel}>{t('weightRecords.stats.totalLoss')}</Text>
           </View>
           <View style={styles.statItem}>
             <Text style={styles.statValue}>{currentWeight.toFixed(1)}kg</Text>
-            <Text style={styles.statLabel}>当前体重</Text>
+            <Text style={styles.statLabel}>{t('weightRecords.stats.currentWeight')}</Text>
           </View>
           <View style={styles.statItem}>
             <Text style={styles.statValue}>{initialWeight.toFixed(1)}kg</Text>
             <View style={styles.statLabelContainer}>
-              <Text style={styles.statLabel}>初始体重</Text>
+              <Text style={styles.statLabel}>{t('weightRecords.stats.initialWeight')}</Text>
               <TouchableOpacity onPress={handleEditInitialWeight} style={styles.editIcon}>
-                <Ionicons name="create-outline" size={14} color="#FF9500" />
+                <Ionicons name="create-outline" size={12} color="#FF9500" />
               </TouchableOpacity>
             </View>
           </View>
           <View style={styles.statItem}>
             <Text style={styles.statValue}>{targetWeight.toFixed(1)}kg</Text>
             <View style={styles.statLabelContainer}>
-              <Text style={styles.statLabel}>目标体重</Text>
+              <Text style={styles.statLabel}>{t('weightRecords.stats.targetWeight')}</Text>
               <TouchableOpacity onPress={handleEditTargetWeight} style={styles.editIcon}>
-                <Ionicons name="create-outline" size={14} color="#FF9500" />
+                <Ionicons name="create-outline" size={12} color="#FF9500" />
               </TouchableOpacity>
             </View>
           </View>
@@ -282,8 +284,8 @@ export default function WeightRecordsPage() {
         ) : (
           <View style={styles.emptyContainer}>
             <View style={styles.emptyContent}>
-              <Text style={styles.emptyText}>暂无体重记录</Text>
-              <Text style={styles.emptySubtext}>点击右上角添加按钮开始记录</Text>
+              <Text style={styles.emptyText}>{t('weightRecords.empty.title')}</Text>
+              <Text style={styles.emptySubtext}>{t('weightRecords.empty.subtitle')}</Text>
             </View>
           </View>
         )}
@@ -309,10 +311,10 @@ export default function WeightRecordsPage() {
                 <Ionicons name="close" size={24} color={themeColors.text} />
               </TouchableOpacity>
               <Text style={[styles.modalTitle, { color: themeColors.text }]}>
-                {pickerType === 'current' && '记录体重'}
-                {pickerType === 'initial' && '编辑初始体重'}
-                {pickerType === 'target' && '编辑目标体重'}
-                {pickerType === 'edit' && '编辑体重记录'}
+                {pickerType === 'current' && t('weightRecords.modal.recordWeight')}
+                {pickerType === 'initial' && t('weightRecords.modal.editInitialWeight')}
+                {pickerType === 'target' && t('weightRecords.modal.editTargetWeight')}
+                {pickerType === 'edit' && t('weightRecords.modal.editRecord')}
               </Text>
               <View style={{ width: 24 }} />
             </View>
@@ -329,21 +331,21 @@ export default function WeightRecordsPage() {
                   </View>
                   <View style={styles.inputWrapper}>
                     <Text style={[styles.weightDisplay, { color: inputWeight ? themeColors.text : themeColors.textSecondary }]}>
-                      {inputWeight || '输入体重'}
+                      {inputWeight || t('weightRecords.modal.inputPlaceholder')}
                     </Text>
-                    <Text style={[styles.unitLabel, { color: themeColors.textSecondary }]}>kg</Text>
+                    <Text style={[styles.unitLabel, { color: themeColors.textSecondary }]}>{t('weightRecords.modal.unit')}</Text>
                   </View>
                 </View>
 
                 {/* Weight Range Hint */}
                 <Text style={[styles.hintText, { color: themeColors.textSecondary }]}>
-                  请输入 0-500 之间的数值，支持小数
+                  {t('weightRecords.modal.inputHint')}
                 </Text>
               </View>
 
               {/* Quick Selection */}
               <View style={styles.quickSelectionSection}>
-                <Text style={[styles.quickSelectionTitle, { color: themeColors.text }]}>快速选择</Text>
+                <Text style={[styles.quickSelectionTitle, { color: themeColors.text }]}>{t('weightRecords.modal.quickSelection')}</Text>
                 <View style={styles.quickButtons}>
                   {[50, 60, 70, 80, 90].map((weight) => (
                     <TouchableOpacity
@@ -358,7 +360,7 @@ export default function WeightRecordsPage() {
                         styles.quickButtonText,
                         inputWeight === weight.toString() && styles.quickButtonTextSelected
                       ]}>
-                        {weight}kg
+                        {weight}{t('weightRecords.modal.unit')}
                       </Text>
                     </TouchableOpacity>
                   ))}
@@ -386,7 +388,7 @@ export default function WeightRecordsPage() {
                 onPress={handleWeightSave}
                 disabled={!inputWeight.trim()}
               >
-                <Text style={styles.saveButtonText}>确定</Text>
+                <Text style={styles.saveButtonText}>{t('weightRecords.modal.confirm')}</Text>
               </TouchableOpacity>
             </View>
           </View>
@@ -461,7 +463,7 @@ const styles = StyleSheet.create({
     alignItems: 'center',
   },
   statValue: {
-    fontSize: 16,
+    fontSize: 14,
     fontWeight: '800',
     color: '#192126',
     marginBottom: 4,
@@ -475,6 +477,7 @@ const styles = StyleSheet.create({
     fontSize: 12,
     color: '#687076',
     marginRight: 4,
+    textAlign: 'center'
   },
   editIcon: {
     padding: 2,