Pre-registered prediction for DESI DR3: the toll model with n = 3 and λ = 1/4 fixed

A pre-registered prediction, recorded on 5 November 2026 before the release of DESI DR3. The companion paper, "Dark energy as a lagged response to black-hole horizon entropy," models dark energy as a vacuum energy that relaxes toward a holographic target set by black-hole horizon entropy. This note fixes both remaining freedoms (relaxation rate n = 3 and coupling λ = 1/4), leaving no free dark-energy parameters and the same parameter count as ΛCDM, and freezes the analysis code by SHA-256 hash. It records the resulting predictions: w0 ≈ −0.87, a phantom crossing near z ≈ 0.56, CPL projection (w0, wa) ≈ (−0.78, −0.73), and the full w(z) curve to z = 2.5. Four tests against DESI DR3 BAO, Planck CMB likelihoods and three supernova samples are stated in advance, with explicit failure criteria. Results will be reported whichever way they go.