R-690 red-proof, 2026-09-25
(1) primaryUnitDirFor with GetStackComposePath as the removed? test:
  FAIL: the restore opens <sys>/felhom-data/backups/primary/nextcloud, want the kept unit <drive>/backups/primary/nextcloud
(2) ListRestorePoints with GetStackComposePath:
  FAIL: the picker offers [] (found=true), want the one kept copy on HDD
Restored: ok
