Make Permutations serializable

src/core/metamorphose.Permutation.scala

@@ -20,6 +20,8 @@ import scala.collection.mutable.BitSet
 import scala.annotation.*
 
 import contingency.*
+import rudiments.*
+import anticipation.*
 
 object Permutation:
 
@@ -50,6 +52,8 @@ case class Permutation(factoradic: Factoradic):
   lazy val lehmer: List[Int] = factoradic.expand
   lazy val expansion: List[Int] = unsafely(apply[Int](List.range(0, lehmer.length)))
 
+  def bytes: Bytes = unsafely(factoradic.number.toByteArray.immutable)
+
   def apply(n: Int): Int = expansion(n)
 
   def apply[ElementType](sequence: List[ElementType]): List[ElementType] raises PermutationError =

src/core/soundness+metamorphose-core.scala

@@ -0,0 +1,3 @@
+package soundness
+
+export metamorphose.{Factoradic, Factorial, Permutation, PermutationError}