Part 2 of the USB/backup spec. agentapi: StatusResponse.Backup record, DueResponse
age_seconds, RestoreTestStatus(). New "Rendszermentés (teljes mentés)" section
(read-only: last backup/target PBS-vs-local/next-due/restore-test) + "Mentés most"
manual trigger that goes through the quiesce loop (controller owns quiescing):
quiesce.Loop gains mutex + TriggerNow() (single-flight, async). New
/api/guest-backup/{trigger,status} (distinct from apiRouter's /api/backup/*).
App-data rows relabeled under an "Alkalmazás-mentések" divider. Config → slice 10.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Quiesce loop resumes (StartStack + clear marker) at the snapshotted phase
instead of done -> downtime whole-backup -> until-snapshot, no consistency loss.
Keeps polling to done/failed (no overlapping backup; post-snapshot failure
observed). Stop-mode fallback to done + crash-safety preserved.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>