Clarify cycle stepper reset inlining

PerfectNumbers.Core/AlphaCalculations.cs

@@ -8,6 +8,8 @@ public static class AlphaCalculations
     {
         int exponent = checked(4 * k + 1);
         EInteger y = PowerCache.Get(p, exponent);
+        // TODO: Reuse pooled numerator/denominator buffers here so the alphaP computation stops allocating
+        // intermediate EInteger instances every invocation.
         return ERational.Create(y * p - 1, y * (p - 1));
     }
 
@@ -15,6 +17,9 @@ public static class AlphaCalculations
     {
         EInteger num = PowerCache.Get(q, a2 + 1) - EInteger.One;
         EInteger den = PowerCache.Get(q, a2) * (q - EInteger.One);
+        // TODO: Reuse pooled ERational builders here so repeated factor computations pull precomputed
+        // numerator/denominator tuples instead of re-executing PowerCache chains each time, matching the
+        // fastest alpha benchmarks.
         return ERational.Create(num, den);
     }
 
@@ -22,7 +27,11 @@ public static class AlphaCalculations
     {
         ERational result = ERational.One;
         for (int i = 0; i < maxR; i++)
+        {
+            // TODO: Replace the repeated Multiply calls with a span-based aggregator that batches factors,
+            // avoiding transient ERational instances when maxR grows large.
             result = result.Multiply(ComputeAlphaFactor(primes[i], a2));
+        }
         return result;
     }
 }