close-management

Runs the month-end close: generates a day-by-day runbook from D-2 to D+5 as CLOSE-<month>.md with an owner matrix, dependency-ordered tasks (subledgers → accruals → reconciliations → flux → lock), numeric flux thresholds, a preparer/reviewer sign-off log, and close metrics such as days-to-close and reopened entries. Use when the user says 'set up our month-end close', 'kick off the June close', or 'our close takes…