Blocks, mutes, bookmarks, pins and reports

- Blocks are per persona and never federate (a Block activity would tell
  the other server who blocked whom): the blocked account is removed as a
  follower, with a Reject{Follow} if it is remote, unfollowed, cleared from
  home and notifications, and refused with Reject if it follows again.
- Mutes (optionally timed, optionally sparing notifications) and per-
  persona domain blocks keep authors out of home timelines, notifications
  and every status list the API returns; the boosts of a hidden author's
  posts are hidden too.
- Bookmarks and pins (at most five, public or unlisted, own posts) with
  their Mastodon endpoints and flags; pinned posts are the actor's
  `featured` collection at /trophies, and `featuredTags` points at
  /tattoos.
- Reports: /api/v1/reports stores the report and, when forwarding to a
  remote account, sends Flag from the instance actor, so the reporting
  persona is never named to the other server. An inbound Flag about a local
  persona or its posts becomes a report; moderators list and resolve them
  under /clientapi/moderator/reports.

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

PrivaPub/Api/Mastodon/Mappers/MastodonMapper.cs

@@ -147,6 +147,13 @@ namespace PrivaPub.Api.Mastodon.Mappers
 			var favourited = viewerId == default
 				? new HashSet<string>()
 				: (await _dbEntities.Favourites.Match(f => f.AccountId == viewerId && ids.Contains(f.PostId)).ExecuteAsync(token)).Select(f => f.PostId).ToHashSet();
+			var bookmarked = viewerId == default
+				? new HashSet<string>()
+				: (await DB.Default.Find<Bookmark>().Match(b => b.AvatarId == viewerId && ids.Contains(b.PostId)).ExecuteAsync(token)).Select(b => b.PostId).ToHashSet();
+			var pinned = (await DB.Default.Find<Pin>().Match(p => ids.Contains(p.PostId)).ExecuteAsync(token)).Select(p => p.PostId).ToHashSet();
+			var hidden = viewerId == default
+				? new HashSet<string>()
+				: await Domain.Relationships.Hidden.AuthorsHiddenFrom(viewerId, all.Select(p => p.ActorURI), forNotifications: false, token);
 			var reblogged = viewerId == default
 				? new HashSet<string>()
 				: (await _dbEntities.Posts.Match(p => p.AuthorAccountId == viewerId && ids.Contains(p.ReblogOfPostId) && !p.DeletedAt.HasValue).ExecuteAsync(token))
@@ -172,6 +179,8 @@ namespace PrivaPub.Api.Mastodon.Mappers
 					FavouritesCount = post.FavouritesCount,
 					Favourited = favourited.Contains(post.ID),
 					Reblogged = reblogged.Contains(post.ID),
+					Bookmarked = bookmarked.Contains(post.ID),
+					Pinned = pinned.Contains(post.ID),
 					Sensitive = post.HasContentWarning,
 					SpoilerText = post.SpoilerText ?? (post.HasContentWarning ? post.Title ?? ActivityPubRenderer.ContentWarning : string.Empty),
 					Visibility = Visibility(post.Visibility),
@@ -186,6 +195,9 @@ namespace PrivaPub.Api.Mastodon.Mappers
 			var mapped = new List<Status>();
 			foreach (var post in posts)
 			{
+				if (hidden.Contains(post.ActorURI) || post.ReblogOfPostId != default && originals.TryGetValue(post.ReblogOfPostId, out var hiddenOriginal)
+					&& hidden.Contains(hiddenOriginal.ActorURI))
+					continue;
 				var status = Map(post);
 				if (status == default)
 					continue;