Mn5Ge3 corrected TB2J bond topology (456 bonds, J reattached from true lattice)

Rebuilt Mn-Mn bond table for Mn5Ge3 (P63/mcm, a=7.194, c=5.061 A; 8 A cutoff): 456 undirected bonds enumerated directly from the reference CIF, each with the TB2J J value reattached via (spin-pair, distance) class matching to the corrupted route output (file a7be7fc5). All 456 classes match exactly; 21 symmetry-split classes averaged (listed in ambiguous_classes). Next: MC rerun on this topology.