Stage B: the encoding-independent orbit obstruction

This is X-Enter's :orbit, included with its proof and exact quantifier XEnter. No Born rule, continuity, injective encoding, dimensional bound, linearity, or amplitude model enters it.

The same proof works for $a(\lambda )=a_0+\lambda c_{\epsilon }$. It does not prove that $\Phi$ is constant on states outside $\mathsf{Enc}(\mathbb{R})$.