P7: Lemmy's Warn and Resolve{Flag}

- A Warn from a community's moderator about a persona's own post there becomes that persona's moderation_warning
  notification (Mastodon's AccountWarning, with the reason and the post), believed from the community's own server or
  from an account the community's moderators collection lists. Remote communities keep that collection's address
  (attributedTo) as ForeignAvatar.ModeratorsURL; it is read only when a warning needs it.
- A Resolve{Flag} for one of our reports (`/grunts/flag-<report id>`) is kept as the report's remote resolution when it
  comes from the server holding what was reported, or the community it was reported to; our own moderators'
  resolution is never replaced. The moderators' report list shows both.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012CzABvBkbcFqoHdmi8b9WB

PrivaPub/Federation/Actors/ActorDocument.cs

@@ -36,6 +36,7 @@ namespace PrivaPub.Federation.Actors
 		public string IconDescription { get; init; }
 		public string HeaderDescription { get; init; }
 		public string MovedTo { get; init; }
+		public string Moderators { get; init; }
 		public List<string> AlsoKnownAs { get; init; } = new();//the accounts it says it also is (a Move's target names the moved one)
 		public DateTime? Published { get; init; }
 		public List<CustomEmoji> Emojis { get; init; } = new();
@@ -92,6 +93,7 @@ namespace PrivaPub.Federation.Actors
 				IconDescription = root.TryGetProperty("icon", out var described) ? Alt(described) : default,
 				HeaderDescription = root.TryGetProperty("image", out var headerImage) ? Alt(headerImage) : default,
 				MovedTo = RemoteActorService.Text(root, "movedTo"),
+				Moderators = type == "Group" ? RemoteActorService.Text(root, "attributedTo") ?? RemoteActorService.Text(root, "moderators") : default,
 				AlsoKnownAs = root.TryGetProperty("alsoKnownAs", out var aliases) ? Uris(aliases) : new(),
 				Published = DateTimeOffset.TryParse(RemoteActorService.Text(root, "published"), CultureInfo.InvariantCulture, DateTimeStyles.AssumeUniversal, out var published)
 					? published.UtcDateTime

PrivaPub/Federation/Actors/RemoteActorService.cs

@@ -234,6 +234,7 @@ namespace PrivaPub.Federation.Actors
 				.Modify(a => a.IsLocked, actor.Locked)
 				.Modify(a => a.IsMemorial, actor.Memorial)
 				.Modify(a => a.MovedToURL, Origin.Of(actor.MovedTo) == default ? default : actor.MovedTo)
+				.Modify(a => a.ModeratorsURL, Origin.Same(actor.Moderators, actor.Id) ? actor.Moderators : default)
 				.Modify(a => a.AlsoKnownAs, actor.AlsoKnownAs)
 				.Modify(a => a.Published, actor.Published)
 				.Modify(a => a.Emojis, actor.Emojis)