Archimedean Shadows: The QEC-Darwinism Tradeoff in Ultrametric Spaces

Maity et al. (arXiv:2608.03944, 2026) proved a tight no-go theorem: QEC and Quantum Darwinism cannot coexist above F_L > 0.874. We audit this through Ostrowski's lens on Bruhat-Tits tree code spaces. v1.10 executes the collective tree-structured fragment refinement (required by v1.8/v1.9): per-depth N_k-qubit blocks with joint Holevo info chi_k^coll = H2((1+cosN_k)/2). Results: (1) first-redundancy boundary moves to F_L ~ 0.83-0.85 (45-65% closer to the theorem threshold 0.874); (2) the residual gap is strongly hierarchy-dependent (17-43x contraction across alpha); (3) honestly reported residual: the gap does not vanish at uniform coupling (0.03-0.044), a remaining model limitation, not a claimed signature. The staircase is preserved and sharpened: R in cumulative sums of N_k with kappa advancing level by level.