TMF ↔ GR/QM: Closing Gap D — Deriving γ from Lⁿ Geometry (Working Document v0.5, corrected)

Third document in the TMF ↔ GR/QM Correspondence Programme series, following v0.4. Addresses Gap D: the status of the free parameters β and γ. A minimal additional postulate P6 (Fibre Proportionality) is introduced; under P6, γ is derived as a [CONDITIONAL DEDUCTION] from TMF postulates P1–P6, and β is precisely characterised as a constrained dimensionless free parameter with geometric interpretation: it measures the rate of fibre projection decay per unit of the dimensionless ratio r_s/(r−r_s). A dimensionally consistent unification is established: γ and its weak-barrier limit γ₀ are two regimes of a single geometric function Λ(ΔV). This version corrects four errors identified by internal audit in the initial v0.5 release, including a dimensional inconsistency in the β derivation and an incorrect geometric assumption about Schwarzschild curvature invariants at the event horizon. Continues: TMF ↔ GR/QM v0.4.