Imports

Section 22.3 - White-path theorem (legacy compatibility path)

Third-edition-numbered compatibility path for the white-path theorem. The canonical fourth-edition source is CLRSLean.FourthEdition.Chapter_20.Section_20_3_DFS.S1_WhitePath; this module forwards to it so legacy imports keep working during the compatibility period (see docs/migrations/clrs4.md).