Claim 4: add UCI-datasets optimal-temperature experiment (T*_in<1, T*_OOD>1 on 6/6), completing the basis-function+UCI claim

Add C3 rank-1 subspace pathology (Prop 5.1) + C4/C5 temperature scaling (cold in-dist, warm OOD); render claim-4/claim-5; add 2 verify scripts

Update logbook: Repro - Gaussian Mean Field VI Predictive Variance