#841 auth 3.0.1: drop local varchar reconciliation (upstreamed as _reconcile_text_columns)

EARS SPEC: - When auth 3.0.1 is deployed, Highway shall remove its local varchar->TEXT reconciliation from initialize_auth_schema (upstream create_tables now runs the identical model-driven pass) and keep the table-existence effect verification. - When migrations run under 3.0.1, the upstream pass shall report zero widened columns (proving our manual pass missed nothing) and the previously reconciled columns shall still read text. - When verified, Highway shall reply to auth thread thr-d99bb6c79b894ff69f16 with the result they asked for.