The inbox answers once it has verified, and processes from the job queue

InboxService is split the way the roadmap lays out Federation/Inbox:
- InboxReceiver reads and verifies the request exactly as before, runs
  the checks that need no fetch (the activity id's origin, a Follow of a
  missing or local-only actor, an Undo of someone else's activity, an
  embedded object attributed to someone else), queues a ProcessInbox job
  and answers 202. The job's dedupe key is the activity id, so a peer that
  delivers the same activity twice is processed once.
- InboxProcessor (two at a time, eight attempts) loads the verified actor
  and hands the activity to the handler for its type.
- Handlers/{Follow,Undo,Create,Delete,Update}Handler are the old methods,
  unchanged except that they no longer produce status codes; the JSON
  helpers live in Objects/ActivityJson and the group membership helpers in
  Inbox/ForeignMembers.

A slow fetch of an object or a remote actor now delays the job, not the
sender's HTTP request.

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

PrivaPub/Federation/Inbox/Handlers/UpdateHandler.cs

@@ -0,0 +1,70 @@
+using MongoDB.Entities;
+
+using PrivaPub.Federation.Actors;
+using PrivaPub.Federation.Objects;
+using PrivaPub.Federation.Outbox;
+using PrivaPub.Federation.Rendering;
+using PrivaPub.Models.Federation;
+using PrivaPub.Models.Group;
+using PrivaPub.Models.Post;
+using PrivaPub.Models.User;
+using PrivaPub.StaticServices;
+
+using System.Text.Json.Nodes;
+
+using static PrivaPub.Federation.Inbox.ForeignMembers;
+using static PrivaPub.Federation.Objects.ActivityJson;
+
+using DmPostEntity = PrivaPub.Models.Post.DmPost;
+using PostEntity = PrivaPub.Models.Post.Post;
+
+namespace PrivaPub.Federation.Inbox.Handlers
+{
+	public class UpdateHandler : IActivityHandler
+	{
+		readonly DbEntities _dbEntities;
+		readonly ILocalActorService _localActors;
+		readonly IRemoteActorService _remoteActors;
+		readonly IDeliveryService _delivery;
+
+		public UpdateHandler(DbEntities dbEntities, ILocalActorService localActors, IRemoteActorService remoteActors, IDeliveryService delivery)
+		{
+			_dbEntities = dbEntities;
+			_localActors = localActors;
+			_remoteActors = remoteActors;
+			_delivery = delivery;
+		}
+
+		public string Type => "Update";
+
+		public async Task Handle(JsonNode activity, ForeignAvatar actor, CancellationToken token)
+		{
+			var update = activity;
+
+			var inner = update["object"];
+			if (Id(inner) == actor.ActorURI)
+			{
+				await _remoteActors.GetActor(actor.ActorURI, refresh: true, token);
+				return;
+			}
+			if (inner is not JsonObject || Id(inner["attributedTo"]) != actor.ActorURI || !Origin.Same(Id(inner), actor.ActorURI))
+				return;
+
+			var objectUri = Id(inner);
+			var text = ContentSanitizer.Html(Value(inner, "content"));
+			await DB.Default.Update<PostEntity>()
+				.Match(p => p.ObjectURI == objectUri && p.ActorURI == actor.ActorURI)
+				.Modify(p => p.Text, text)
+				.Modify(p => p.ContentHtml, text)
+				.Modify(p => p.UpdateDate, DateTime.UtcNow)
+				.ExecuteAsync(token);
+			await DB.Default.Update<DmPostEntity>()
+				.Match(p => p.ObjectURI == objectUri && p.ActorURI == actor.ActorURI)
+				.Modify(p => p.Text, text)
+				.Modify(p => p.ContentHtml, text)
+				.Modify(p => p.UpdateDate, DateTime.UtcNow)
+				.ExecuteAsync(token);
+			return;
+				}
+	}
+}