A follow of a persona's profile page; an Update under its Create's id

Forte follows a persona by its profile page (/@name, WebFinger's alias) rather than its actor's id: Follow and
Undo{Follow} now find the persona by either (it was a 404). Forte also sends an edit only added to the thread's context
(FEP-171b), under the same activity id as the post's Create: the unwrapping now tells two activities that share an id
apart by what they carry, as the inbox does, so the Update is not taken for a copy.

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

PrivaPub/Federation/Inbox/Handlers/FollowHandler.cs

@@ -43,7 +43,7 @@ namespace PrivaPub.Federation.Inbox.Handlers
 			var follow = activity;
 			var follower = actor;
 
-			var target = await _localActors.FindByUri(Id(follow["object"]), token);
+			var target = await _localActors.FindByAddress(Id(follow["object"]), token);
 			if (target is not { IsFederated: true } || target.Kind == LocalActorKind.Application)
 			{
 				Arrival.Drop("unknown-recipient");

PrivaPub/Federation/Inbox/Handlers/UndoHandler.cs

@@ -83,7 +83,7 @@ namespace PrivaPub.Federation.Inbox.Handlers
 		{
 			var followers = await _dbEntities.Followers.Match(f => f.ActorURI == actor.ActorURI).ExecuteAsync(token);
 			var targetUri = inner is JsonObject ? Id(inner["object"]) : default;
-			var target = targetUri == default ? default : await _localActors.FindByUri(targetUri, token);
+			var target = targetUri == default ? default : await _localActors.FindByAddress(targetUri, token);
 			var undone = false;
 			foreach (var follower in followers)
 			{