UCT No-New-Constants Prediction 2: Five-Level Quantum Readout Floor (Pre-Registration, Stage 1)

Stage 1 pre-registration of a no-new-constants forward prediction derived from the UCT compression-interface theorem at d = 5. Predicts the structured readout floor f_U(5) = 24/25 = 0.9600 for U(5)-covariant readout, with primary discriminator f_{Z_2^5} = 31/32 = 0.96875 for sign-channel readout. Contains: theoretical input, prediction and discriminator, five-criterion architecture classifier, mundane-source noise budget with pre-test gate, statistical-power requirement, Bayes-factor decision ru