feat: добавил ограничение записи на лекции

backend/UniVerse.Api.Tests/Users/UserServiceTests.cs

@@ -44,6 +44,33 @@ public class UserServiceTests
         Assert.Null(stats.NextLevelXp);
     }
 
+    [Fact]
+    public async Task GetStatsAsync_ReturnsEnrollmentSlotStateAndRules()
+    {
+        await using var db = CreateDbContext();
+        SeedLevelThresholds(db);
+        var now = DateTime.UtcNow;
+        db.Users.Add(new User { Id = 1, Email = "student@test.local", Xp = 350 });
+        db.Courses.Add(new Course { Id = 1, Name = "Course" });
+        db.Lectures.AddRange(
+            Lecture(1, now.AddDays(1)),
+            Lecture(2, now.AddDays(2)),
+            Lecture(3, now.AddDays(-1)));
+        db.LectureEnrollments.AddRange(
+            new LectureEnrollment { LectureId = 1, UserId = 1 },
+            new LectureEnrollment { LectureId = 2, UserId = 1 },
+            new LectureEnrollment { LectureId = 3, UserId = 1 });
+        await db.SaveChangesAsync();
+        var service = CreateService(db);
+
+        var stats = await service.GetStatsAsync(1);
+
+        Assert.Equal(3, stats.ActiveEnrollments);
+        Assert.Equal(5, stats.EnrollmentSlotLimit);
+        Assert.Equal(new[] { 1, 3, 4 }, stats.EnrollmentSlotRules.Select(rule => rule.Level));
+        Assert.Equal(new[] { 3, 5, 7 }, stats.EnrollmentSlotRules.Select(rule => rule.Slots));
+    }
+
     private static AppDbContext CreateDbContext()
     {
         var options = new DbContextOptionsBuilder<AppDbContext>()
@@ -77,4 +104,15 @@ public class UserServiceTests
             new LevelThreshold { Level = 3, RequiredXp = 300 });
         db.SaveChanges();
     }
+
+    private static Lecture Lecture(int id, DateTime startsAt) => new()
+    {
+        Id = id,
+        CourseId = 1,
+        Title = $"Lecture {id}",
+        StartsAt = startsAt,
+        EndsAt = startsAt.AddHours(2),
+        IsOpen = true,
+        MaxEnrollments = 30
+    };
 }