Add CPU by-divisor tester and integrate interface

PerfectNumbers.Core.Tests/MersenneNumberDivisorCpuTesterTests.cs

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+using System;
+using FluentAssertions;
+using PerfectNumbers.Core.Cpu;
+using Xunit;
+
+namespace PerfectNumbers.Core.Tests;
+
+public class MersenneNumberDivisorCpuTesterTests
+{
+        [Fact]
+        [Trait("Category", "Fast")]
+        public void ByDivisor_tester_tracks_divisors_across_primes()
+        {
+                var tester = new MersenneNumberDivisorByDivisorCpuTester();
+                tester.ConfigureFromMaxPrime(11UL);
+
+                tester.IsPrime(5UL, out bool divisorsExhausted).Should().BeTrue();
+                divisorsExhausted.Should().BeTrue();
+
+                tester.IsPrime(7UL, out divisorsExhausted).Should().BeTrue();
+                divisorsExhausted.Should().BeTrue();
+
+                tester.IsPrime(11UL, out divisorsExhausted).Should().BeFalse();
+                divisorsExhausted.Should().BeTrue();
+        }
+
+        [Fact]
+        [Trait("Category", "Fast")]
+        public void ByDivisor_session_checks_divisors_across_primes()
+        {
+                var tester = new MersenneNumberDivisorByDivisorCpuTester();
+                tester.ConfigureFromMaxPrime(13UL);
+
+                using var session = tester.CreateDivisorSession();
+                ulong[] primes = { 5UL, 7UL, 11UL, 13UL };
+                byte[] hits = new byte[primes.Length];
+
+                ulong cycle23 = MersenneDivisorCycles.CalculateCycleLength(23UL);
+                session.CheckDivisor(23UL, cycle23, primes, hits);
+                hits.Should().ContainInOrder(new byte[] { 0, 0, 1, 0 });
+
+                Array.Fill(hits, (byte)0);
+                ulong cycle31 = MersenneDivisorCycles.CalculateCycleLength(31UL);
+                session.CheckDivisor(31UL, cycle31, primes, hits);
+                hits.Should().ContainInOrder(new byte[] { 1, 0, 0, 0 });
+        }
+}
+