Higgs Avatar of the Bank: The R⁸ Response-Higgs Pivot, 7 Seals, and the Collider Ladder Signature

Abstract (v3 insert) We present a symmetry-protected microphysical layer that upgrades the “Higgs Avatar of the Bank” interface to a robust, auditable construction. The electroweak sector is extended to an S₃-symmetric three-Higgs-doublet model (3HDM) supplemented by an inert Z₂ parity, realizing the pattern “1 active + 2 inert”: a single SM-like Higgs doublet (the S₃ singlet) carries the observed electroweak order parameter, while an S₃-doublet pair remains VEV-less and Yukawa-forbidden. This arrangement (i) suppresses tree-level flavour-changing neutral currents by construction, (ii) provides a stable Z₂-odd inert spectrum (with dark-matter candidate(s) in standard inert-3HDM fashion), and (iii) implements “triadic stiffness” via a common/relative decomposition of the inert pair. A heavy relative mode acts as a gapped stabilizer (syndrome channel): any symmetry-breaking perturbation necessarily excites the relative mode and is suppressed at low probe scale by κ²/m₋², while common-mode response remains admissible. The multi-threshold inert spectrum naturally yields a DC-suppressing high-pass response template that can be mapped to the Seven-Seals transfer-function fingerprint across probe scales κ ∈ {q, ω}. We conclude with a PASS/FAIL certification checklist and entry-point references for 3HDM symmetry systematics, S₃-inspired vacua, alignment, and inert-3HDM phenomenology.