Handle zero-cycle GPU divisor sessions with heuristics

PerfectNumbers.Core.Tests/MersenneNumberDivisorGpuTesterTests.cs

@@ -142,6 +142,22 @@ public class MersenneNumberDivisorGpuTesterTests
         divisorsExhausted.Should().BeTrue();
     }
 
+    [Fact]
+    [Trait("Category", "Fast")]
+    public void ByDivisor_session_computes_cycle_when_zero_is_provided()
+    {
+        var tester = new MersenneNumberDivisorByDivisorGpuTester();
+        tester.ConfigureFromMaxPrime(43UL);
+
+        using var session = tester.CreateDivisorSession();
+        ulong[] primes = { 31UL, 37UL, 41UL };
+        byte[] hits = new byte[primes.Length];
+
+        session.CheckDivisor(223UL, MontgomeryDivisorData.FromModulus(223UL), 0UL, primes, hits);
+
+        hits.Should().ContainInOrder(new byte[] { 0, 1, 0 });
+    }
+
     [Fact]
     [Trait("Category", "Fast")]
     public void ByDivisor_session_checks_divisors_across_primes()