feat: 实现减脂体重管理App完整功能

- 实现拍照识别食物功能（集成大语言模型视觉能力）
- 实现智能对话功能（集成大语言模型流式输出）
- 实现食物记录和卡路里管理功能
- 实现体重记录和统计功能
- 实现健康数据管理页面
- 配置数据库表结构（用户、食物记录、体重记录）
- 实现Express后端API路由
- 配置Tab导航和前端页面
- 采用健康运动配色方案

client/screens/stats/styles.ts

@@ -0,0 +1,161 @@
+import { StyleSheet } from 'react-native';
+import { Spacing, BorderRadius, Theme } from '@/constants/theme';
+
+export const createStyles = (theme: Theme) => {
+  return StyleSheet.create({
+    scrollContent: {
+      flexGrow: 1,
+      paddingHorizontal: Spacing.lg,
+      paddingTop: Spacing.xl,
+      paddingBottom: Spacing["5xl"],
+    },
+    header: {
+      flexDirection: 'row',
+      justifyContent: 'space-between',
+      alignItems: 'center',
+      marginBottom: Spacing.xl,
+    },
+    addButton: {
+      width: 40,
+      height: 40,
+      borderRadius: BorderRadius.lg,
+      backgroundColor: theme.primary,
+      justifyContent: 'center',
+      alignItems: 'center',
+      shadowColor: theme.primary,
+      shadowOffset: { width: 0, height: 2 },
+      shadowOpacity: 0.2,
+      shadowRadius: 8,
+      elevation: 3,
+    },
+    chartSection: {
+      padding: Spacing.xl,
+      borderRadius: BorderRadius.xl,
+      marginBottom: Spacing.lg,
+    },
+    sectionHeader: {
+      flexDirection: 'row',
+      justifyContent: 'space-between',
+      alignItems: 'center',
+      marginBottom: Spacing.lg,
+    },
+    sectionTitle: {
+      marginBottom: Spacing.lg,
+    },
+    emptyText: {
+      textAlign: 'center',
+      paddingVertical: Spacing["2xl"],
+    },
+    recordsList: {
+      gap: Spacing.md,
+    },
+    recordItem: {
+      flexDirection: 'row',
+      justifyContent: 'space-between',
+      alignItems: 'center',
+      padding: Spacing.lg,
+      backgroundColor: theme.backgroundTertiary,
+      borderRadius: BorderRadius.lg,
+    },
+    recordInfo: {
+      flex: 1,
+    },
+    recordWeight: {
+      flexDirection: 'row',
+      alignItems: 'baseline',
+      marginBottom: Spacing.xs,
+    },
+    changeBadge: {
+      flexDirection: 'row',
+      alignItems: 'center',
+      paddingHorizontal: Spacing.sm,
+      paddingVertical: Spacing.xs,
+      backgroundColor: theme.backgroundDefault,
+      borderRadius: BorderRadius.sm,
+      marginRight: Spacing.md,
+    },
+    statsSection: {
+      padding: Spacing.xl,
+      borderRadius: BorderRadius.xl,
+      marginBottom: Spacing.lg,
+    },
+    statRow: {
+      flexDirection: 'row',
+      justifyContent: 'space-between',
+    },
+    statItem: {
+      flex: 1,
+      alignItems: 'center',
+    },
+    statBorder: {
+      borderLeftWidth: 1,
+      borderRightWidth: 1,
+      borderColor: theme.border,
+    },
+    modalContainer: {
+      flex: 1,
+      backgroundColor: 'rgba(0, 0, 0, 0.5)',
+      justifyContent: 'center',
+      alignItems: 'center',
+      padding: Spacing.lg,
+    },
+    modalContent: {
+      width: '100%',
+      maxWidth: 400,
+      borderRadius: BorderRadius["2xl"],
+    },
+    modalHeader: {
+      flexDirection: 'row',
+      justifyContent: 'space-between',
+      alignItems: 'center',
+      padding: Spacing.xl,
+      borderBottomWidth: 1,
+      borderBottomColor: theme.border,
+    },
+    modalBody: {
+      padding: Spacing.xl,
+    },
+    inputGroup: {
+      marginBottom: Spacing.lg,
+    },
+    label: {
+      marginBottom: Spacing.sm,
+    },
+    input: {
+      backgroundColor: theme.backgroundTertiary,
+      borderRadius: BorderRadius.lg,
+      paddingHorizontal: Spacing.lg,
+      paddingVertical: Spacing.md,
+      color: theme.textPrimary,
+      fontSize: 16,
+    },
+    textArea: {
+      height: 80,
+      textAlignVertical: 'top',
+    },
+    modalFooter: {
+      flexDirection: 'row',
+      gap: Spacing.md,
+      padding: Spacing.xl,
+      borderTopWidth: 1,
+      borderTopColor: theme.border,
+    },
+    modalButton: {
+      flex: 1,
+      paddingVertical: Spacing.lg,
+      borderRadius: BorderRadius.lg,
+      alignItems: 'center',
+    },
+    cancelButton: {
+      backgroundColor: theme.backgroundTertiary,
+    },
+    confirmButton: {
+      backgroundColor: theme.primary,
+      shadowColor: theme.primary,
+      shadowOffset: { width: 0, height: 2 },
+      shadowOpacity: 0.2,
+      shadowRadius: 8,
+      elevation: 3,
+    },
+  });
+};