滑动续期与自动刷新：

Web：访问令牌 10 分钟；活跃时自动轮换刷新令牌；连续无操作 30 分钟后清除登录并跳转登录页。
App：会话窗口 3 天；打开 App、恢复前台或请求接口时自动刷新并重新顺延 3 天。
普通登录和 SSO 使用同一策略。
刷新令牌只以 SHA-256 摘要入库，每次刷新都会轮换，旧令牌无法再次使用；退出登录会吊销刷新令牌。
网络临时故障不会误清登录状态，多标签页同时刷新也做了竞争处理。

tests/Jiaowu.Api.Tests/AuthSessionServiceTests.cs

@@ -0,0 +1,133 @@
+using Jiaowu.Api.Domain.Identity;
+using Jiaowu.Api.Infrastructure.Auth;
+using Jiaowu.Api.Infrastructure.Persistence;
+using Microsoft.AspNetCore.Identity;
+using Microsoft.Data.Sqlite;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace Jiaowu.Api.Tests;
+
+public sealed class AuthSessionServiceTests
+{
+    [Fact]
+    public async Task Web_session_rotates_refresh_token_and_rejects_reuse()
+    {
+        await using var fixture = await SessionFixture.CreateAsync();
+
+        var issued = await fixture.Service.CreateAsync(
+            fixture.User,
+            [SystemRoles.Student],
+            AuthenticationClientType.Web);
+
+        Assert.InRange(
+            issued.SessionExpiresAt,
+            DateTime.UtcNow.AddMinutes(29),
+            DateTime.UtcNow.AddMinutes(31));
+        var stored = await fixture.Db.RefreshSessions.SingleAsync();
+        Assert.NotEqual(issued.RefreshToken, stored.TokenHash);
+
+        var refreshed = await fixture.Service.RefreshAsync(issued.RefreshToken);
+
+        Assert.NotNull(refreshed);
+        Assert.NotEqual(issued.RefreshToken, refreshed.RefreshToken);
+        Assert.Null(await fixture.Service.RefreshAsync(issued.RefreshToken));
+        Assert.Equal(1, await fixture.Db.RefreshSessions.CountAsync(x => x.RevokedAt == null));
+    }
+
+    [Fact]
+    public async Task App_session_uses_three_day_sliding_window()
+    {
+        await using var fixture = await SessionFixture.CreateAsync();
+
+        var issued = await fixture.Service.CreateAsync(
+            fixture.User,
+            [SystemRoles.Student],
+            AuthenticationClientType.App);
+
+        Assert.InRange(
+            issued.SessionExpiresAt,
+            DateTime.UtcNow.AddDays(3).AddMinutes(-1),
+            DateTime.UtcNow.AddDays(3).AddMinutes(1));
+    }
+
+    private sealed class SessionFixture : IAsyncDisposable
+    {
+        private readonly SqliteConnection _connection;
+        private readonly ServiceProvider _provider;
+        private readonly AsyncServiceScope _scope;
+
+        private SessionFixture(
+            SqliteConnection connection,
+            ServiceProvider provider,
+            AsyncServiceScope scope,
+            AppDbContext db,
+            ApplicationUser user,
+            IAuthSessionService service)
+        {
+            _connection = connection;
+            _provider = provider;
+            _scope = scope;
+            Db = db;
+            User = user;
+            Service = service;
+        }
+
+        public AppDbContext Db { get; }
+        public ApplicationUser User { get; }
+        public IAuthSessionService Service { get; }
+
+        public static async Task<SessionFixture> CreateAsync()
+        {
+            var connection = new SqliteConnection("Data Source=:memory:");
+            await connection.OpenAsync();
+            var services = new ServiceCollection();
+            services.AddLogging();
+            services.AddDbContext<AppDbContext>(options => options.UseSqlite(connection));
+            services.Configure<JwtOptions>(options =>
+            {
+                options.Issuer = "tests";
+                options.Audience = "tests-web";
+                options.Key = "a-test-signing-key-that-is-at-least-32-bytes-long";
+                options.AccessTokenMinutes = 10;
+                options.WebIdleMinutes = 30;
+                options.AppIdleMinutes = 4320;
+            });
+            services
+                .AddIdentityCore<ApplicationUser>()
+                .AddRoles<ApplicationRole>()
+                .AddEntityFrameworkStores<AppDbContext>();
+            services.AddScoped<ITokenService, TokenService>();
+            services.AddScoped<IAuthSessionService, AuthSessionService>();
+
+            var provider = services.BuildServiceProvider();
+            var scope = provider.CreateAsyncScope();
+            var db = scope.ServiceProvider.GetRequiredService<AppDbContext>();
+            await db.Database.EnsureCreatedAsync();
+            var userManager = scope.ServiceProvider.GetRequiredService<UserManager<ApplicationUser>>();
+            var user = new ApplicationUser
+            {
+                UserName = "session-user",
+                DisplayName = "会话测试用户",
+                IsEnabled = true,
+                LockoutEnabled = true
+            };
+            Assert.True((await userManager.CreateAsync(user, "SessionUser@123")).Succeeded);
+
+            return new SessionFixture(
+                connection,
+                provider,
+                scope,
+                db,
+                user,
+                scope.ServiceProvider.GetRequiredService<IAuthSessionService>());
+        }
+
+        public async ValueTask DisposeAsync()
+        {
+            await _scope.DisposeAsync();
+            await _provider.DisposeAsync();
+            await _connection.DisposeAsync();
+        }
+    }
+}