Initial commit: HealthManager full-stack health management platform

Backend: .NET 10 + PostgreSQL + EF Core + JWT + SignalR
Frontend patient: React 19 + TypeScript + Vite (mobile H5)
Frontend doctor: React 19 + TypeScript + Vite (desktop web)

backend/src/HealthManager.Domain/Entities/ExerciseRecord.cs

@@ -0,0 +1,16 @@
+namespace HealthManager.Domain.Entities;
+
+public class ExerciseRecord
+{
+    public Guid Id { get; set; }
+    public Guid UserId { get; set; }
+    public string ExerciseType { get; set; } = string.Empty;
+    public int DurationMin { get; set; }
+    public string? Intensity { get; set; } // low, moderate, high
+    public int? CaloriesBurned { get; set; }
+    public string? Notes { get; set; }
+    public DateOnly RecordedAt { get; set; }
+    public DateTime CreatedAt { get; set; } = DateTime.UtcNow;
+
+    public User User { get; set; } = null!;
+}