d(G/T)/dT simplifies to -H/T²; residual 0 (operator-level identity)

Sympy-exact symbolic witness of the Gibbs-Helmholtz identity at the operator level. Setup: write G(T) = H − T S treating (H, S) as T-independent constants (valid when C_p → 0 or when the integral over ΔC_p vanishes — the 'simplest'…