Imports

Section 4.4 - The recursion-tree method (legacy compatibility path)

Third-edition-numbered compatibility path for the recursion-tree method. The canonical fourth-edition source is CLRSLean.FourthEdition.Chapter_04.Section_04_4_Recursion_Tree_Method; this module forwards to it so legacy imports keep working during the compatibility period (see docs/migrations/clrs4.md).