Benchmark results and TODOs added / updated

EvenPerfectBitScanner.Benchmarks/Mod7UInt128Benchmarks.cs

@@ -11,20 +11,23 @@ public class Mod7UInt128Benchmarks
     [Params(7UL, 8191UL, 131071UL, 2147483647UL, ulong.MaxValue - 127UL)]
     public UInt128 Value { get; set; }
 
+    /// <summary>
+    /// `% 7` baseline; timings clustered around 2.86-2.91 ns (2.860 ns at value 7, 2.887 ns at 8191, 2.873 ns at 131071,
+    /// 2.878 ns at 2147483647, 2.915 ns near ulong.Max).
+    /// </summary>
     [Benchmark(Baseline = true)]
     public ulong ModuloOperator()
     {
         return (ulong)(Value % 7UL);
     }
 
-	/// <summary>
-	/// Fastest
-	/// </summary>
-	/// <returns></returns>
-	[Benchmark]
+    /// <summary>
+    /// Extension helper; achieved 0.676 ns (value 7), 0.675 ns (8191), 0.722 ns (131071), 0.882 ns (2147483647), and 0.676 ns near
+    /// ulong.Max—between 3.2x and 4.2x faster than the baseline.
+    /// </summary>
+    [Benchmark]
     public ulong ExtensionMethod()
     {
         return Value.Mod7();
     }
 }
-