A backup is restored at boot, and never undoes a protective act

PrivaPub admin restore <id> (and soon the administrator's page) checks the backup (same host, a format and newest
migration this build reads, every hash) and writes restore.json; the running service sees it within seconds and stops,
and the next start restores it in MaintenanceGate, before migrations, indexes and hosted services: a pre-restore backup
taken once, every collection dropped and imported raw with its indexes, the media the live directory lacks brought
back, then the protective merge from the pre-restore backup. Followers and follows are the live ones; blocks, mutes,
domain blocks, reserved names, tombstones, reports, filters and OAuth applications are the union; deletions win;
accounts made since become tombstones and local posts made since answer 410; every session ends.

Each attempt redoes everything; one refused before any change is abandoned and recorded, one failed midway exits 1 for
systemd to retry, and after three it exits 75, which the unit no longer restarts. Commands wait (exit 75) while a
restore is pending. RestoreRecord tells what happened (admin restore --status).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LsXgEaXee4GCU1hwYgPJXw

PrivaPub/Infrastructure/Backup/RestoreMarker.cs

@@ -12,6 +12,7 @@ namespace PrivaPub.Infrastructure.Backup
 		public string Backup { get; set; }//the backup restored
 		public string PreRestore { get; set; }//the backup taken just before, what the protective merge reads
 		public string State { get; set; } = "pending";//pending, then running
+		public string RequestedBy { get; set; }//who asked: a root's name, or "cli"
 		public int Attempts { get; set; }
 		public DateTime RequestedAt { get; set; } = DateTime.UtcNow;
 		public string Error { get; set; }
@@ -29,7 +30,8 @@ namespace PrivaPub.Infrastructure.Backup
 			}
 			catch (JsonException)
 			{
-				return default;
+				//never written half (Write is atomic): someone's hand; the server won't guess what was meant
+				return new RestoreMarker { State = "unreadable", Attempts = MaxAttempts, Error = $"{FileName} can't be read" };
 			}
 		}