Filters: words and posts a persona would rather not see

Mastodon's v2 filters replace the empty stubs: a filter's title, contexts,
action (warn, hide, blur) and expiry, its keywords (whole words or not,
taken as JSON objects, listed or numbered form fields, with id and _destroy
on update) and its statuses, each with their own endpoints; the v1 API is
the same filters seen keyword by keyword. Every status a persona reads
carries the filters it matches in `filtered` (a boost as what it boosts),
matched as Mastodon matches: warning, title, text, poll options and media
descriptions. Clients apply context and action. Filters never federate, and
go with a deleted persona.

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

PrivaPub/Api/Mastodon/Mappers/MastodonMapper.cs

@@ -197,6 +197,7 @@ namespace PrivaPub.Api.Mastodon.Mappers
 			var hidden = viewerId == default || !hideFromViewer
 				? new HashSet<string>()
 				: await Domain.Relationships.Hidden.AuthorsHiddenFrom(viewerId, all.Select(p => p.ActorURI), forNotifications: false, token);
+			var filters = await Domain.Social.Filters.Of(viewerId, 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))
@@ -238,7 +239,8 @@ namespace PrivaPub.Api.Mastodon.Mappers
 					EmojiReactions = reactions.GetValueOrDefault(post.ID) ?? new(),
 					Pleroma = new PleromaStatus { EmojiReactions = reactions.GetValueOrDefault(post.ID) ?? new() },
 					Mentions = post.Mentions.Where(m => !m.Silent).Select(m => Mention(m, mentionAccounts)).Where(m => m != default).ToList(),
-					Tags = post.Tags.Select(t => new StatusTag { Name = t, Url = ActivityPubRenderer.TagUrl(_localActors.BaseAddress, t) }).ToList()
+					Tags = post.Tags.Select(t => new StatusTag { Name = t, Url = ActivityPubRenderer.TagUrl(_localActors.BaseAddress, t) }).ToList(),
+					Filtered = filters.Of(post)
 				};
 				return status;
 			}
@@ -287,6 +289,7 @@ namespace PrivaPub.Api.Mastodon.Mappers
 						continue;
 					Quote(inner, original);
 					status.Reblog = inner;
+					status.Filtered = inner.Filtered;//a boost is filtered as what it boosts
 					status.Url = inner.Url;//a boost has no page of its own; /grunts would answer JSON to a browser
 					status.Content = string.Empty;
 					status.Reblogged = reblogged.Contains(original.ID);