Clarify cycle stepper reset inlining

PerfectNumbers.Core/InputParser.cs

@@ -10,16 +10,22 @@ public static class InputParser
         if (value.Contains('^'))
         {
             var parts = value.Split('^');
+            // TODO: Replace Split/Parse with the span-based exponent parser so BigInteger inputs avoid allocations
+            // and leverage the Utf8Parser fast paths benchmarked for CLI numeric parsing.
             BigInteger b = BigInteger.Parse(parts[0], CultureInfo.InvariantCulture);
             int e = int.Parse(parts[1], CultureInfo.InvariantCulture);
             return BigInteger.Pow(b, e);
         }
 
+        // TODO: Replace BigInteger.Parse(string) with the span overload once callers provide ReadOnlySpan<char> so
+        // we can route through the allocation-free Utf8Parser-based helpers.
         return BigInteger.Parse(value, CultureInfo.InvariantCulture);
     }
 
     public static decimal ParseDecimal(string value)
     {
+        // TODO: Swap decimal.Parse for the Utf8Parser-based decimal reader so callers avoid culture-aware conversions
+        // on the hot configuration path.
         return decimal.Parse(value, CultureInfo.InvariantCulture);
     }
 }