First computational upper bound on the infimum for Erdős Problem #1038

We compute the first rigorous upper bound on the infimum of the sublevel set measure |{x ∈ ℝ : |f(x)| < 1}| for monic polynomials f of degree n with all real roots in [-1,1] (Erdős Problem #1038).
Main result: inf ≤ 1.837 (N=200 configuration), a 35% improvement over the Borwein–Erdélyi–Kós (1999) lower bound of 24/3−1 ≈ 1.520.
Extremal structure: The minimizing configuration is a discrete atom-plus-cloud measure: a heavy atom at +1 (weight ≈ 0.826) plus an arcsine-type cloud on [−1, −0.800] (weight ≈ 0.174). This is consistent with Tao's Lemma 3.2 (atom weight ≥ 1/2 at ±1). The sublevel set has a two-component structure: a main interval of width ≈ 1.837 plus a tiny secondary lobe of width ≈ 0.035, separated by a gap at x = 0 (the L₁ Lagrange point of the binary configuration).
Extrapolation: Power-law fit on N = 40–120 gives M∞ = 1.8336 ± 0.0007, consistent with 11/6 ≈ 1.8333 (unproven conjecture).
Includes: structured results (JSON), reproducibility checksum (SHA-256), Rust source code for the sublevel measure evaluator, optimized configurations for N = 80 and N = 100, and full experimental report.