Measurement Layer (Width, Encapsulation, Participation, Exposure) (v1.0)

This paper defines the four primary measurement quantities of the Branch Admissibility System: Width (W), Encapsulation (E), Participation, and Exposure. These quantities provide a non-generative, non-causal description of competitive structure under constraint, without introducing learning mechanisms or representation normalization. The paper specifies closed definitions for each variable and establishes their structural separation from signal activation, authority redistribution, and causal ex