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

hooks/useAuthGuard.ts

@@ -5,6 +5,7 @@ import { Alert } from 'react-native';
 
 import { ROUTES } from '@/constants/Routes';
 import { useAppDispatch, useAppSelector } from '@/hooks/redux';
+import { useI18n } from '@/hooks/useI18n';
 import { STORAGE_KEYS, api } from '@/services/api';
 import { logout as logoutAction } from '@/store/userSlice';
 
@@ -21,6 +22,7 @@ export function useAuthGuard() {
   const dispatch = useAppDispatch();
   const currentPath = usePathname();
   const user = useAppSelector(state => state.user);
+  const { t } = useI18n();
 
   // 判断登录状态：优先使用 token，因为 token 是登录的根本凭证
   // profile.id 可能在初始化时还未加载，但 token 已经从 AsyncStorage 恢复
@@ -74,28 +76,28 @@ export function useAuthGuard() {
       router.push('/auth/login');
     } catch (error) {
       console.error('退出登录失败:', error);
-      Alert.alert('错误', '退出登录失败，请稍后重试');
+      Alert.alert(t('authGuard.logout.error'), t('authGuard.logout.errorMessage'));
     }
-  }, [dispatch, router]);
+  }, [dispatch, router, t]);
 
   // 带确认对话框的退出登录
   const confirmLogout = useCallback(() => {
     Alert.alert(
-      '确认退出',
-      '确定要退出当前账号吗？',
+      t('authGuard.confirmLogout.title'),
+      t('authGuard.confirmLogout.message'),
       [
         {
-          text: '取消',
+          text: t('authGuard.confirmLogout.cancelButton'),
           style: 'cancel',
         },
         {
-          text: '确定',
+          text: t('authGuard.confirmLogout.confirmButton'),
           style: 'default',
           onPress: handleLogout,
         },
       ]
     );
-  }, [handleLogout]);
+  }, [handleLogout, t]);
 
   // 注销账号功能
   const handleDeleteAccount = useCallback(async () => {
@@ -109,38 +111,38 @@ export function useAuthGuard() {
       // 执行退出登录逻辑
       await dispatch(logoutAction()).unwrap();
 
-      Alert.alert('账号已注销', '您的账号已成功注销', [
+      Alert.alert(t('authGuard.deleteAccount.successTitle'), t('authGuard.deleteAccount.successMessage'), [
         {
-          text: '确定',
+          text: t('authGuard.deleteAccount.confirmButton'),
           onPress: () => router.push('/auth/login'),
         },
       ]);
     } catch (error: any) {
       console.error('注销账号失败:', error);
-      const message = error?.message || '注销失败，请稍后重试';
-      Alert.alert('注销失败', message);
+      const message = error?.message || t('authGuard.deleteAccount.errorMessage');
+      Alert.alert(t('authGuard.deleteAccount.errorTitle'), message);
     }
-  }, [dispatch, router]);
+  }, [dispatch, router, t]);
 
   // 带确认对话框的注销账号
   const confirmDeleteAccount = useCallback(() => {
     Alert.alert(
-      '确认注销账号',
-      '此操作不可恢复，将删除您的账号及相关数据。确定继续吗？',
+      t('authGuard.confirmDeleteAccount.title'),
+      t('authGuard.confirmDeleteAccount.message'),
       [
         {
-          text: '取消',
+          text: t('authGuard.confirmDeleteAccount.cancelButton'),
           style: 'cancel',
         },
         {
-          text: '确认注销',
+          text: t('authGuard.confirmDeleteAccount.confirmButton'),
           style: 'destructive',
           onPress: handleDeleteAccount,
         },
       ],
       { cancelable: true }
     );
-  }, [handleDeleteAccount]);
+  }, [handleDeleteAccount, t]);
 
   return {
     isLoggedIn,