Imports

Section 26.4 - Push-relabel algorithms (legacy compatibility path)

Third-edition-numbered compatibility path for the push-relabel preflow model. The canonical fourth-edition source is CLRSLean.FourthEdition.Chapter_24.Section_24_4_Push_Relabel; this module forwards to it so legacy imports keep working during the compatibility period (see docs/migrations/clrs4.md).