Section 26.2 - Executable breadth-first search (legacy compatibility path)
Third-edition-numbered compatibility path for the executable residual BFS. The canonical
fourth-edition source is
CLRSLean.FourthEdition.Chapter_24.Section_24_2_Edmonds_Karp.S4_ExecutableBFS;
this module forwards to it so legacy imports keep working during the
compatibility period (see docs/migrations/clrs4.md).