audit-round

External-audit role for arcgentic rounds. Loaded when arcgentic state.yaml is in awaiting_audit or audit_in_progress, OR when the user explicitly requests an external audit of a finished round, OR when reviewing a handoff doc + commit chain against the round's declared scope. Produces a PASS / NEEDS_FIX / AUDIT_INCOMPLETE verdict document with mechanically-verifiable fact table, structured findings (P0-P3), and…