Residue/GeneralizedTheorem (legacy stub)

The original file under Residue/GeneralizedTheorem.lean re-declared generalizedResidueTheorem at root namespace, clashing with the canonical GeneralizedResidueTheory.GeneralizedResidueTheorem (which is the version that other parts of the project — Cycle.lean, ViazovskaMagicFunction.lean — actually import). We retire this duplicate as a re-export.