Jeva: System One Models from First Principles

Jeva is a decision-native architecture designed to address four structural requirements for system one models: null-awareness, permutation-invariance, option-scalability, and cacheability. It uses a shared encoder to independently represent requests and options, with a compact decision stack refining request state against immutable option memory. Symmetric aggregation produces permutation-equivariant probabilities, and a separate coverage estimate distinguishes answer absence from candidate competition.