Posts reach their audience, edits follow them, deletes leave a tombstone

OutboxPublisher works out who a post goes to, Mastodon's way: followers'
shared inboxes for public, unlisted and followers-only; every mentioned
remote account's own inbox; the recipients only for direct; the parent's
author for a reply; a community's followers for a post in it; nobody for
a circle. Creates, updates and deletes all use it.

- Local posts take a visibility (public, unlisted, followers-only) and a
  spoiler text next to the content-warning flag.
- /clientapi/post/update keeps the previous version as a revision,
  re-renders, and sends Update{Note} with `updated` to the same to/cc.
- Deleting is now soft: the content, title, spoiler, media and revisions
  are cleared, timeline entries removed, the parent's reply count goes
  down, Delete goes to the stored audience, and the object answers 410
  with a Tombstone instead of 404.
- Editing a persona's profile sends Update{Person} to its followers.

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

PrivaPub/Services/ClientToServer/Private/IPrivateAvatarUsersService.cs

@@ -10,6 +10,7 @@ using PrivaPub.Models.User;
 using PrivaPub.Resources;
 using PrivaPub.StaticServices;
 using PrivaPub.Federation.Actors;
+using PrivaPub.Federation.Outbox;
 
 namespace PrivaPub.Services.ClientToServer.Private
 {
@@ -23,16 +24,19 @@ namespace PrivaPub.Services.ClientToServer.Private
 	public class PrivateAvatarUsersService : IPrivateAvatarUsersService
 	{
 		readonly ILocalActorService _localActors;
+		readonly IOutboxPublisher _outbox;
 		readonly DbEntities _dbEntities;
 		readonly IStringLocalizer<GenericRes> _localizer;
 		readonly ILogger<PrivateAvatarUsersService> _logger;
 
 		public PrivateAvatarUsersService(ILocalActorService localActors,
+			IOutboxPublisher outbox,
 			DbEntities dbEntities,
 			IStringLocalizer<GenericRes> localizer,
 			ILogger<PrivateAvatarUsersService> logger)
 		{
 			_localActors = localActors;
+			_outbox = outbox;
 			_dbEntities = dbEntities;
 			_localizer = localizer;
 			_logger = logger;
@@ -115,6 +119,7 @@ namespace PrivaPub.Services.ClientToServer.Private
 					avatar.Settings = ToSettings(form.Settings);
 				avatar.UpdatedAt = DateTime.UtcNow;
 				await DB.Default.SaveAsync(avatar);
+				await _outbox.PublishProfile(_localActors.FromAvatar(avatar), default);
 
 				result.Data = ToView(avatar);
 				return result;