P6: custom emoji, fuller remote profiles, and polls both ways

- Custom emoji (Emoji tags) on posts, display names, bios and profile fields, at most 64 per object, proxied, in
  Status.emojis and Account.emojis.
- Remote profiles keep their header, profile fields, locked flag, published date, movedTo, indexable, memorial and
  image descriptions (a locked GoToSocial account no longer shows as open).
- Polls: incoming Questions (Mastodon, Misskey, Pleroma, GoToSocial shapes) with counts, voters, end and closed;
  our own polls from the Mastodon API go out as Questions; votes in are counted once per voter and never become
  replies; personas vote on other servers' polls with one Note per choice; counts refresh with an Update at most every
  three minutes; a poll closes on time and tells its voters and its author. GET /api/v1/polls/:id and POST
  /api/v1/polls/:id/votes.
- An Update without a newer `updated` only refreshes poll, video, audio and event details and leaves no revision.

Checked live against GoToSocial: each side's poll reaches the other as a poll and each side's vote is counted.

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

PrivaPub/Federation/Inbox/Handlers/CreateHandler.cs

@@ -4,6 +4,7 @@ using MongoDB.Entities;
 using PrivaPub.Domain.Timelines;
 using PrivaPub.Federation.Actors;
 using PrivaPub.Federation.Moderation;
+using PrivaPub.Domain.Statuses;
 using PrivaPub.Federation.Objects;
 using PrivaPub.Federation.Outbox;
 using PrivaPub.Infrastructure.Ids;
@@ -35,11 +36,13 @@ namespace PrivaPub.Federation.Inbox.Handlers
 		readonly IRemotePosts _remotePosts;
 		readonly IGroupDistributor _groups;
 		readonly IObjectRecords _records;
+		readonly IPollService _polls;
 
 		public CreateHandler(DbEntities dbEntities, ILocalActorService localActors, IRemoteActorService remoteActors, IDeliveryService delivery,
-			IDomainBlocks domainBlocks, IFanout fanout, IRemotePosts remotePosts, IGroupDistributor groups, IObjectRecords records)
+			IDomainBlocks domainBlocks, IFanout fanout, IRemotePosts remotePosts, IGroupDistributor groups, IObjectRecords records, IPollService polls)
 		{
 			_records = records;
+			_polls = polls;
 			_groups = groups;
 			_fanout = fanout;
 			_remotePosts = remotePosts;
@@ -64,6 +67,15 @@ namespace PrivaPub.Federation.Inbox.Handlers
 			var note = NoteParser.Parse(node);
 			if (note == default || note.AttributedTo != author.ActorURI)
 				return;
+			if (note.Title != default && note.InReplyTo != default && ObjectShapes.Text(note.ContentHtml, 1) == default)
+			{
+				var question = await _dbEntities.Posts.Match(p => p.ObjectURI == note.InReplyTo && p.Poll != null).ExecuteFirstAsync(token);
+				if (question != default)
+				{
+					await _polls.Receive(question, author, note.Title, Id(activity), token);
+					return;
+				}
+			}
 			if (await _dbEntities.Posts.Match(p => p.ObjectURI == note.Id).ExecuteAnyAsync(token)
 				|| await DB.Default.Find<DeletedObject>().Match(d => d.ObjectURI == note.Id).ExecuteAnyAsync(token))
 				return;