Draw down endurance for one loaded self-powered traverse.
Total weighted weight this body bears (carried + worn + held).
What this body can comfortably carry (physiology-derived).
Burden / capacity (dimensionless; 0 capacity → 0/Infinity).
Absolute lift cap = capacity × OVERLOAD_FACTOR.
Would lifting candidate (as loose carry) push burden past the ceiling?
The public surface added by LoadBearingMixin.