Sharp local stability and critical-exponent sensitivity of Ptolemaic split metrics

Unrefereed mathematical candidate. Exact attained first-order stability constants at the specified complete split Ptolemaic metrics, universal rational-function certificates, explicit nonlinear realisation and local quadratic remainders, and sharp critical-exponent sensitivities.

This corrected v0.3.1 release replaces optimisation-sensitive assertions with explicit checks. The complete tables and machine-readable certificates are indispensable proof supplements. Local theorems are distinct from companion-dependent global equality interpretations. No formal proof-assistant verification, authenticated external specialist review, unaffiliated reproduction or exhaustive priority determination is claimed.

Original prose and data: CC0-1.0. Original code: MIT. Retained historical inputs and cited third-party material retain their own terms; see LICENSES.md.