Перевести FakeDiscoveryPacer на NSubstitute

Первый фейк из чек-листа задачи #1: Substitute.For<IDiscoveryPacer>, счётчики
DelayCalls -> Received/DidNotReceive, колбэк OnDelay -> When/Do. Фейк удалён,
тесты 1340 зелёные.

src/core/tests/Deal.Tests.Unit/Contracts/DiscoveryWorkerServiceTests.cs

@@ -1,9 +1,11 @@
 using Deal.Contracts.Integrations.Models;
+using Deal.Modules.Discovery.Application.Abstractions;
 using Deal.Modules.Discovery.Application.Models;
+using Deal.Tests.Unit.Modules.Discovery;
 using Deal.Modules.Discovery.Application.Services;
 using Deal.Modules.Settings.Application.Models;
-using Deal.Tests.Unit.Modules.Discovery;
 using Deal.Tests.Unit.Modules.Settings;
+using NSubstitute;
 using Grpc.Core;
 
 namespace Deal.Tests.Unit.Contracts;
@@ -263,7 +265,7 @@ public sealed class DiscoveryWorkerServiceTests
         DiscoveryWorkerOutcome outcome = await fx.Worker.TickOnceAsync(CancellationToken.None);
 
         Assert.Equal((DiscoveryWorkerService.ActionJoin, "dt_1"), (outcome.Action, outcome.TaskId));
-        Assert.Equal(1, fx.Pacer.DelayCalls); // пауза между вступлениями была (в проде 50–70 с)
+        await fx.Pacer.Received(1).WaitJoinDelayAsync(Arg.Any<CancellationToken>()); // пауза между вступлениями была (в проде 50–70 с)
         Assert.Equal(["grp1"], fx.Gateway.JoinedUsernames);
         DiscoveryCandidateDto candidate = fx.Store.Candidates.Single();
         Assert.Equal(DiscoveryCandidateStatuses.Joined, candidate.Status);
@@ -326,7 +328,7 @@ public sealed class DiscoveryWorkerServiceTests
         Assert.Equal(DiscoveryWorkerService.ActionError, first.Action);
         Assert.Equal(DiscoveryWorkerService.ActionError, second.Action);
         Assert.Equal(DiscoveryWorkerService.ActionSkip, third.Action); // 3-я неудача — кандидат удаляется (python L417–420)
-        Assert.Equal(3, fx.Pacer.DelayCalls);
+        await fx.Pacer.Received(3).WaitJoinDelayAsync(Arg.Any<CancellationToken>());
         Assert.Empty(fx.Store.Candidates);
         Assert.Contains(fx.Store.Log, log => log.Event == DiscoveryLogEvents.Skip && log.Text.Contains("не удалось вступить (3 попытки)"));
     }
@@ -338,7 +340,8 @@ public sealed class DiscoveryWorkerServiceTests
         fx.Store.SeedTask(Task("dt_1", searchDone: true, autoJoin: true));
         fx.Store.SeedCandidate(Candidate("d1", "dt_1", DiscoveryCandidateStatuses.Review, username: "grp1"));
         // За «паузу» 50–70 с задачу поставили на паузу вручную: повторная проверка после паузы → выход без join.
-        fx.Pacer.OnDelay = () => fx.Tasks.PauseAsync("dt_1", CancellationToken.None).GetAwaiter().GetResult();
+        fx.Pacer.When(x => x.WaitJoinDelayAsync(Arg.Any<CancellationToken>()))
+            .Do(_ => fx.Tasks.PauseAsync("dt_1", CancellationToken.None).GetAwaiter().GetResult());
 
         DiscoveryWorkerOutcome outcome = await fx.Worker.TickOnceAsync(CancellationToken.None);
 
@@ -361,7 +364,7 @@ public sealed class DiscoveryWorkerServiceTests
 
         Assert.Equal(DiscoveryWorkerService.ActionNone, outcome.Action);
         Assert.Empty(fx.Gateway.JoinedUsernames);
-        Assert.Equal(0, fx.Pacer.DelayCalls); // join никому нельзя — пауза даже не запрашивалась (python L480–481)
+        await fx.Pacer.DidNotReceive().WaitJoinDelayAsync(Arg.Any<CancellationToken>()); // join никому нельзя — пауза даже не запрашивалась (python L480–481)
     }
 
     [Fact]
@@ -417,7 +420,7 @@ public sealed class DiscoveryWorkerServiceTests
         FakeDiscoveryStore Store,
         FakeSettingsStore Settings,
         FakeDiscoveryGateway Gateway,
-        FakeDiscoveryPacer Pacer,
+        IDiscoveryPacer Pacer,
         DiscoveryWorkerService Worker,
         DiscoveryTasksService Tasks);
 
@@ -436,7 +439,7 @@ public sealed class DiscoveryWorkerServiceTests
         var planGuard = new DiscoveryPlanGuard(store, settings);
         var tasks = new DiscoveryTasksService(store, planGuard, settings);
         var banGuard = new DiscoveryBanGuard(store, settings);
-        var pacer = new FakeDiscoveryPacer();
+        var pacer = Substitute.For<IDiscoveryPacer>();
         var gateway = new FakeDiscoveryGateway();
         var worker = new DiscoveryWorkerService(
             store, tasks, candidates, log, new DiscoveryEvaluator(settings, ml, ai), banGuard, pacer, gateway);

src/core/tests/Deal.Tests.Unit/Modules/Discovery/FakeDiscoveryPacer.cs

@@ -1,27 +0,0 @@
-using Deal.Modules.Discovery.Application.Abstractions;
-
-namespace Deal.Tests.Unit.Modules.Discovery;
-
-/// <summary>
-/// Фейковый <see cref="IDiscoveryPacer"/> для тестов воркера Discovery
-/// </summary>
-public sealed class FakeDiscoveryPacer : IDiscoveryPacer
-{
-    /// <summary>
-    /// Действие, выполняемое в момент паузы
-    /// </summary>
-    public Action? OnDelay { get; set; }
-
-    /// <summary>
-    /// Сколько раз запрошена пауза перед авто-вступлением
-    /// </summary>
-    public int DelayCalls { get; private set; }
-
-    /// <inheritdoc />
-    public Task WaitJoinDelayAsync(CancellationToken ct)
-    {
-        DelayCalls++;
-        OnDelay?.Invoke();
-        return Task.CompletedTask;
-    }
-}