Fe10B2C2 — TCTP-TCSP p1/3 k4 Co-free variant (Co→Fe) - prerelax

Co-free TCTP-TCSP p1/3 k4 variant. All 4 Co sites replaced with Fe in the relaxed Fe6B2C2Co4 scaffold (P2/m, 14 atoms/cell). Prerelax — submitted for Orb v3 relaxation.