Section 10.4 - Representing rooted trees (legacy compatibility path)
Third-edition-numbered compatibility path for representing rooted trees. The
canonical fourth-edition source is
CLRSLean.FourthEdition.Chapter_10.Section_10_3_Representing_Rooted_Trees
(fourth-edition §10.3); this module forwards to it so legacy imports keep
working during the compatibility period (see docs/migrations/clrs4.md).