DCRP-03: Logarithmic Model-Cone Debt and Scale-Return Exclusion

Replaces the previously failed raw-tax accumulation route with a scale-invariant logarithmic model-cone debt identity, checked directly against the MORP recurrence-return test, resolving in one stroke the two open problems left by the previous round (scale-normalized recurrence does not imply equal endpoint kinetic energy; a fixed-scale critical raw toll can still be geometrically additive).