feat: 后端架构重构 — Endpoint→Service→Repository分层 + AI确认机制 + 异步任务持久化

- 核心业务拆分为 Endpoint → Application Service → Repository 三层
- AI写入操作必须用户确认后才写库(确认卡片机制)
- 报告/饮食/用药分析改为持久化任务队列(原子领取/重试/重启恢复)
- 运动计划修复: 连续真实日期替代周模板
- 用药提醒去重 + 通知Outbox预留
- 认证收拢到AuthService, 管理员收拢到AdminService
- AI会话加用户归属校验防串号
- 提示词调整为患者视角
- 开发假数据已关闭
- 21/21测试通过, 0警告0错误

backend/src/Health.Infrastructure/HealthArchives/EfHealthArchiveRepository.cs

@@ -0,0 +1,17 @@
+using Health.Application.HealthArchives;
+
+namespace Health.Infrastructure.HealthArchives;
+
+public sealed class EfHealthArchiveRepository(AppDbContext db) : IHealthArchiveRepository
+{
+    private readonly AppDbContext _db = db;
+
+    public Task<HealthArchive?> GetByUserIdAsync(Guid userId, CancellationToken ct) =>
+        _db.HealthArchives.FirstOrDefaultAsync(a => a.UserId == userId, ct);
+
+    public async Task AddAsync(HealthArchive archive, CancellationToken ct) =>
+        await _db.HealthArchives.AddAsync(archive, ct);
+
+    public Task SaveChangesAsync(CancellationToken ct) =>
+        _db.SaveChangesAsync(ct);
+}