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/tests/Health.Tests/persistence_pipeline_tests.cs

@@ -0,0 +1,76 @@
+using Health.Infrastructure.AI;
+using Health.Infrastructure.Data;
+using Health.Infrastructure.Data.Records;
+using Health.Infrastructure.Reports;
+using Microsoft.EntityFrameworkCore;
+
+namespace Health.Tests;
+
+public sealed class PersistencePipelineTests
+{
+    [Fact]
+    public async Task AiConfirmation_CanOnlyBeTakenOnceByOwner()
+    {
+        await using var db = CreateDbContext();
+        var store = new EfAiWriteConfirmationStore(db);
+        var ownerId = Guid.NewGuid();
+        var command = await store.CreateAsync(ownerId, "record_health_data", "{}", TimeSpan.FromMinutes(10), CancellationToken.None);
+
+        var wrongUser = await store.TakeAsync(command.Id, Guid.NewGuid(), CancellationToken.None);
+        var firstTake = await store.TakeAsync(command.Id, ownerId, CancellationToken.None);
+        var secondTake = await store.TakeAsync(command.Id, ownerId, CancellationToken.None);
+
+        Assert.Null(wrongUser);
+        Assert.NotNull(firstTake);
+        Assert.Null(secondTake);
+    }
+
+    [Fact]
+    public async Task ReportTask_RetryUsesBackoffBeforeMaxAttempts()
+    {
+        await using var db = CreateDbContext();
+        var task = NewReportTask(attempts: 1);
+        db.ReportAnalysisTasks.Add(task);
+        await db.SaveChangesAsync();
+        var queue = new EfReportAnalysisQueue(db);
+        var before = DateTime.UtcNow;
+
+        await queue.RetryAsync(task.Id, "temporary failure", CancellationToken.None);
+
+        Assert.Equal("Pending", task.Status);
+        Assert.True(task.AvailableAt > before);
+        Assert.Equal("temporary failure", task.LastError);
+    }
+
+    [Fact]
+    public async Task ReportTask_RetryMarksFailedAtMaxAttempts()
+    {
+        await using var db = CreateDbContext();
+        var task = NewReportTask(attempts: 3);
+        db.ReportAnalysisTasks.Add(task);
+        await db.SaveChangesAsync();
+        var queue = new EfReportAnalysisQueue(db);
+
+        await queue.RetryAsync(task.Id, new string('x', 2500), CancellationToken.None);
+
+        Assert.Equal("Failed", task.Status);
+        Assert.Equal(2000, task.LastError!.Length);
+    }
+
+    private static ReportAnalysisTaskRecord NewReportTask(int attempts) => new()
+    {
+        Id = Guid.NewGuid(),
+        ReportId = Guid.NewGuid(),
+        FilePath = "report.jpg",
+        Status = "Processing",
+        Attempts = attempts,
+        AvailableAt = DateTime.UtcNow,
+        CreatedAt = DateTime.UtcNow,
+        UpdatedAt = DateTime.UtcNow,
+    };
+
+    private static AppDbContext CreateDbContext() => new(
+        new DbContextOptionsBuilder<AppDbContext>()
+            .UseInMemoryDatabase(Guid.NewGuid().ToString())
+            .Options);
+}