Sox v1.2: Extensivity as a Jurisdiction Criterion for Bulk Phase Coherence

This release formalizes extensivity as a necessary ontological condition for macroscopic phase coherence within the Sox framework. A phase is shown to qualify as bulk only if its phase capacity scales superadditively with system size. This criterion eliminates finite-size false positives and formally distinguishes genuine macroscopic phases from locally coherent but globally fragile states. No dynamics or phenomenology are introduced. The formally verified Lean source code is maintained at:https://github.com/josemichellpr/sox_lean/blob/main/Sox_Extensivity.lean