Increase coverage with identity and filter tests

GameList.Tests/MiddlewareTests.cs

@@ -25,4 +25,15 @@ public class MiddlewareTests
         Assert.Equal(HttpStatusCode.Unauthorized, resp.StatusCode);
         Assert.Contains(resp.Headers, h => h.Key.Equals("Set-Cookie", StringComparison.OrdinalIgnoreCase));
     }
+
+    [Fact]
+    public async Task Existing_player_passes_through_middleware()
+    {
+        using var factory = new TestWebApplicationFactory();
+        var client = factory.CreateClientWithCookies();
+        await client.RegisterAsync("live");
+
+        var resp = await client.GetAsync("/api/state");
+        Assert.Equal(HttpStatusCode.OK, resp.StatusCode);
+    }
 }