POST /prompt_manager/maintenance/apply {token} starts a maintenance job
(records admission, not cancellable, groups changed/protected/errors).
The token is consumed on the loop turn the job starts: a second apply is
409 plan-used naming the job, a busy refusal keeps the token, an unknown
or expired one is 410 plan-expired, and a restore since the review is
409 storage-changed.
With the safety backup policy on (maintenance.safety_backup, default true,
saved through the settings route with the revision), the job first writes
a backup into a temp file beside the database, makes it a standalone
rollback-journal file, verifies it, fsyncs it and renames it onto a unique
<db>.backup_<YYYYmmdd_HHMMSS_ffffff>[_n] name; any failure leaves no file
and nothing changed. The apply then rechecks the reviewed fingerprint
inside BEGIN IMMEDIATE (plan-changed writes nothing), deletes in batches of
400 ids, counts changed and protected records, logs the backup by name
only and prunes old safety backups. With the policy off the log and the
status line say "No safety backup".
POST /prompt_manager/maintenance/preview reviews duplicate_prompts,
optimize, unused_components or missing_links on its own mode=ro snapshot
and answers a Plan (scope, protected reasons, backup policy, media, at most
50 detail rows). The fingerprint, targets and judged sources stay in a
server-side PlanStore under a single-use token (15 min, 8 plans, 16 MiB,
never truncated; a restart forgets them), bound to the database it read.
The previews reuse the legacy queries: duplicate groups and the merge are
shared with cleanup_duplicates, ORPHANED_PROMPTS_SQL is built from the
#239 protection predicates the plan reports, and missing links are judged
by the health check's link_states. Legacy /maintenance keeps its shape;
vacuum now reports success:false when VACUUM fails, and
cleanup_orphaned_images skips links under unavailable sources.
Vito Sansevero