prove2me-logs: the Diaz tree's free half is closed — frontier at four leaves

A second Sep 8 session on the Diaz tree closed the free half: no admissible matrix exists there, and that is now proved, after which norm_free closes onto the published statement (S) and the frontier stands at four leaves. The log also publishes an SFE route the session’s other model proved and withheld, records the lesson that the relation you are using is the one that breaks your argument, and scopes the next target with a brief for the four-exponentials theorem at transcendence degree one.