Defect Holonomy in the Minimal and Embedded Reduced Transport Sector

Under the hypotheses of T36, the unique Gray-class closure defect is shown to lift to a genuine two-level skew-Hermitian rotation generator on the defect support H_d = span{|8⟩, |24⟩}. Five results are established. On the minimal defect sector, in the ordered basis (|8⟩, |24⟩): E_d = iσ_y, E_d² = −I, E_d⁴ = I. The holonomy U_d(θ) = eθE_d = I·cos θ + E_d·sin θ is unitary and realizes an SO(2)-rotation on the defect plane. Under the canonical quarter-turn normalization τ = 1 from T36: U_τ = e(π/2)E_d = E_d. The holonomy flips the local grading: {E_d, Z} = 0 and U_τ·Z·U_τ⁻¹ = −Z. When embedded into the larger reduced transport system H_red = H_d ⊕ H_r, the defect survives as a dressed iσ_y-type generator with effective defect projection coefficient: λ_eff(θ) = 1 + ⟨E_d, A⟩ − ⟨E_d, B(θI − D)⁻¹C⟩ The defect holonomy persists under embedding whenever λ_eff(θ) ≠ 0. Whether Q5-induced residual coupling forbids exact cancellation in all cases is not proved here; that is, the open non-cancellation question and the natural next theorem target. Status: Minimal two-state matrix form, rotation-generator algebra, unitary holonomy formula, quarter-turn normalization, grading inversion, embedded block form, and effective coefficient formula are all solid by direct matrix computation. Embedded persistence conditional on λ_eff(θ) ≠ 0, non-cancellation under actual Q5-induced residual coupling not yet proved from first principles. All results inherit T36 hypotheses and T16/T17/T20 conditionality. Dependencies: T1, T2, T7, T14, T15, T16, T17, T18, T19, T20, T29, T30, T34, T35, T36.