POST /maintenance/preview {operation: "rotated_logs", options: {}} lists the
rotated copies Rule R allows, with size and time, and what it keeps (the
active log, links, other files); it writes nothing and answers the Plan
shape with basenames only, backup policy none and no disk key.
POST /maintenance/apply starts the "Rotated log copies" maintenance job
(admission read: runs beside a scan, refused beside another maintenance job
or an exclusive one). It deletes exactly the reviewed copies, or nothing and
fails plan-changed when any of them changed after the review; a copy that
cannot be deleted becomes an errors row. The token is consumed on the loop
turn the job starts. (#329)