Initial commit: 健康管家 AI 健康陪伴助手

- Backend: .NET 10 Minimal API + EF Core + PostgreSQL
- Frontend: Flutter + Riverpod + GoRouter + Dio
- AI: DeepSeek LLM + Qwen VLM (OpenAI-compatible)
- Auth: SMS + JWT (access/refresh tokens)
- Features: AI chat, health tracking, medication management, diet analysis, exercise plans, doctor consultations, report analysis

backend/src/Health.Domain/Entities/DietRecord.cs

@@ -0,0 +1,39 @@
+using Health.Domain.Enums;
+
+namespace Health.Domain.Entities;
+
+/// <summary>
+/// 饮食记录
+/// </summary>
+public sealed class DietRecord
+{
+    public Guid Id { get; set; }
+    public Guid UserId { get; set; }
+    public MealType MealType { get; set; }
+    public int? TotalCalories { get; set; }
+    public int? HealthScore { get; set; } // 1-5 星
+    public DateOnly RecordedAt { get; set; }
+    public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
+
+    public User User { get; set; } = null!;
+    public ICollection<DietFoodItem> FoodItems { get; set; } = [];
+}
+
+/// <summary>
+/// 饮食记录中的食物条目
+/// </summary>
+public sealed class DietFoodItem
+{
+    public Guid Id { get; set; }
+    public Guid DietRecordId { get; set; }
+    public string Name { get; set; } = string.Empty;
+    public string? Portion { get; set; }
+    public int? Calories { get; set; }
+    public decimal? ProteinGrams { get; set; }
+    public decimal? CarbsGrams { get; set; }
+    public decimal? FatGrams { get; set; }
+    public string? Warning { get; set; }
+    public int SortOrder { get; set; }
+
+    public DietRecord DietRecord { get; set; } = null!;
+}