Move List's path enumeration into list.go, position into node.go and sortedNames into sorted.go

graph.go

@@ -3,7 +3,6 @@ package fejkdata
 import (
 	"fmt"
 	"slices"
-	"sort"
 
 	"github.com/larvit/fejkdata/internal/invariant"
 )
@@ -88,15 +87,6 @@ func namedNodes(m map[string]node) []namedNode {
 	return out
 }
 
-func sortedNames[V any](m map[string]V) []string {
-	names := make([]string, 0, len(m))
-	for name := range m {
-		names = append(names, name)
-	}
-	sort.Strings(names)
-	return names
-}
-
 // renderEdge is a child a node renders into, labelled by what reaches it (a field
 // name, reference, or choice index) for a readable cycle report.
 type renderEdge struct {