Section 4.2 - Strassen's algorithm (legacy compatibility path)
Third-edition-numbered compatibility path for Strassen's matrix-multiplication
algorithm. The canonical fourth-edition source is
CLRSLean.FourthEdition.Chapter_04.Section_04_2_Strassen_Algorithm;
this module forwards to it so legacy imports keep working during the
compatibility period (see docs/migrations/clrs4.md).