Fix Task 5 review issues: per-test ApiFactory, drop dead RoleManager param + EF Core using

backend.tests/AuthTests.cs

@@ -5,14 +5,13 @@ using Xunit;
 
 namespace backend.tests;
 
-public class AuthTests(ApiFactory factory) : IClassFixture<ApiFactory>
+public class AuthTests
 {
-    private readonly ApiFactory _factory = factory;
-
     [Fact]
     public async Task Register_then_login_then_me_returns_user()
     {
-        var client = _factory.CreateClient();
+        using var factory = new ApiFactory();
+        var client = factory.CreateClient();
 
         var reg = await client.PostAsJsonAsync("/api/auth/register",
             new { email = "first@example.com", password = "Passw0rd!" });
@@ -30,7 +29,8 @@ public class AuthTests(ApiFactory factory) : IClassFixture<ApiFactory>
     [Fact]
     public async Task Me_without_login_returns_401()
     {
-        var client = _factory.CreateClient();
+        using var factory = new ApiFactory();
+        var client = factory.CreateClient();
         var res = await client.GetAsync("/api/auth/me");
         res.StatusCode.Should().Be(HttpStatusCode.Unauthorized);
     }
@@ -38,11 +38,12 @@ public class AuthTests(ApiFactory factory) : IClassFixture<ApiFactory>
     [Fact]
     public async Task First_user_is_admin()
     {
-        var client = _factory.CreateClient();
+        using var factory = new ApiFactory();
+        var client = factory.CreateClient();
         await client.PostAsJsonAsync("/api/auth/register",
-            new { email = "first@example.com", password = "Passw0rd!" });
+            new { email = "admin@example.com", password = "Passw0rd!" });
         await client.PostAsJsonAsync("/api/auth/login",
-            new { email = "first@example.com", password = "Passw0rd!" });
+            new { email = "admin@example.com", password = "Passw0rd!" });
 
         var me = await client.GetAsync("/api/auth/me");
         (await me.Content.ReadAsStringAsync()).Should().Contain("\"isAdmin\":true");