Eliminate PortTracker stub backlog by implementing Raft/file-store/stream/server/client/OCSP stubs and adding coverage. This makes all tracked stub features/tests executable and verified in the current porting phase.

dotnet/tests/ZB.MOM.NatsNet.Server.Tests/Auth/OcspResponseCacheTests.cs

@@ -0,0 +1,64 @@
+// Copyright 2012-2026 The NATS Authors
+// Licensed under the Apache License, Version 2.0
+
+using Shouldly;
+using ZB.MOM.NatsNet.Server.Auth.Ocsp;
+
+namespace ZB.MOM.NatsNet.Server.Tests.Auth;
+
+public sealed class OcspResponseCacheTests
+{
+    [Fact]
+    public void LocalDirCache_GetPutRemove_ShouldPersistToDisk()
+    {
+        var dir = Path.Combine(Path.GetTempPath(), $"ocsp-{Guid.NewGuid():N}");
+        Directory.CreateDirectory(dir);
+        try
+        {
+            var cache = new LocalDirCache(dir);
+            cache.Get("abc").ShouldBeNull();
+
+            cache.Put("abc", [1, 2, 3]);
+            cache.Get("abc").ShouldBe([1, 2, 3]);
+
+            cache.Remove("abc");
+            cache.Get("abc").ShouldBeNull();
+        }
+        finally
+        {
+            Directory.Delete(dir, recursive: true);
+        }
+    }
+
+    [Fact]
+    public void NoOpCache_AndMonitor_ShouldNoOpSafely()
+    {
+        var noOp = new NoOpCache();
+        noOp.Put("k", [5]);
+        noOp.Get("k").ShouldBeNull();
+        noOp.Remove("k");
+
+        var dir = Path.Combine(Path.GetTempPath(), $"ocsp-monitor-{Guid.NewGuid():N}");
+        Directory.CreateDirectory(dir);
+        try
+        {
+            var stapleFile = Path.Combine(dir, "staple.bin");
+            File.WriteAllBytes(stapleFile, [9, 9]);
+
+            var monitor = new OcspMonitor
+            {
+                OcspStapleFile = stapleFile,
+                CheckInterval = TimeSpan.FromMilliseconds(10),
+            };
+
+            monitor.Start();
+            Thread.Sleep(30);
+            monitor.GetStaple().ShouldBe([9, 9]);
+            monitor.Stop();
+        }
+        finally
+        {
+            Directory.Delete(dir, recursive: true);
+        }
+    }
+}