Section 28.1 - Solving systems of linear equations (legacy compatibility path)
Third-edition-numbered compatibility path for the LUP decomposition and LUP-SOLVE. The canonical
fourth-edition source is
CLRSLean.FourthEdition.Chapter_28.Section_28_1_Linear_Equations;
this module forwards to it so legacy imports keep working during the
compatibility period (see docs/migrations/clrs4.md).