R6 moderation: roles, silence and suspension, bans that write nothing on the personas, deletions, report actions

Roles (user, moderator, administrator) from the CLI and /clientapi/admin/roots/{id}/role, never one's own nor the last
administrator. Silence keeps an account's posts out of public timelines, hashtags, trends, search and relays while its
followers still get them; suspension refuses and revokes a local persona's tokens, answers 404 for its posts and
collections, holds back every delivery and tells other servers nothing new, its actor unchanged; a suspended remote
account's activities are dropped and nothing goes to its own inbox (a shared one still serves its server). A banned
login's personas are held back in memory alone (Restrictions), so nothing pairs them in stored data. Personas and groups
are deleted one at a time (PersonaRemoval, GroupRemoval), by their login or an administrator with the password. Reports
resolve with an action and a note; posts are taken down, a remote copy hidden. Warnings reach the persona as Mastodon's
moderation_warning. Every staff act goes to the staff's log. Migration _020 limits posts from servers already silenced;
a restore keeps the moderation made since the backup.

Verified: interop.sh moderation gts mastodon with SecureMode, 194 passed; restore.sh, 25 passed, now with a suspension,
a silence and a takedown made after the backup.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WpVCoDeM1qUTRp4fXQdfof

PrivaPub/Infrastructure/Data/Indexes.cs

@@ -62,6 +62,14 @@ namespace PrivaPub.Infrastructure.Data
 
 			await Unique<ForeignAvatar>(a => a.ActorURI, Builders<ForeignAvatar>.Filter.Gt(a => a.ActorURI, ""), token);
 			await Plain<ForeignAvatar>(token, a => a.PublicKeyId);
+			// the staff's moderation (R6): the moderated accounts, here and elsewhere, and the posts taken down
+			await Plain<ForeignAvatar>(token, a => a.SuspendedAt);
+			await Plain<ForeignAvatar>(token, a => a.SilencedAt);
+			await Plain<Avatar>(token, a => a.SuspendedAt);
+			await Plain<Avatar>(token, a => a.SilencedAt);
+			await DB.Default.Index<Post>().Key(p => p.ModeratedAt, KeyType.Ascending)
+				.Option(o => o.PartialFilterExpression = Builders<Post>.Filter.Type(p => p.ModeratedAt, MongoDB.Bson.BsonType.DateTime))
+				.CreateAsync(token);
 
 			await DB.Default.Index<Follower>()
 				.Key(f => f.LocalActorId, KeyType.Ascending)