Edit history from formerRepresentations

Pleroma and Akkoma send a post's earlier versions with it. A post PrivaPub first meets after its edits now has its
history, and an edit that carries them brings the versions missed in between; each is read as the post itself is. The
Akkoma scenario checks a post fetched after two edits by an account no persona follows.

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

PrivaPub/Federation/Inbox/RemoteEdits.cs

@@ -13,7 +13,7 @@ namespace PrivaPub.Federation.Inbox
 {
 	public static class RemoteEdits
 	{
-		public const int MaxRevisions = 20;
+		public const int MaxRevisions = NoteParser.MaxRevisions;
 
 		//newer than what we hold; or, for a first edit, no older and actually different, because GoToSocial's timestamps are
 		//whole seconds and an edit made in the second the post was published carries updated == published
@@ -47,14 +47,18 @@ namespace PrivaPub.Federation.Inbox
 				return false;
 			}
 
-			post.Revisions.Add(new PostRevision
-			{
-				Title = post.Title,
-				SpoilerText = post.SpoilerText,
-				ContentHtml = post.ContentHtml,
-				HasContentWarning = post.HasContentWarning,
-				EditedAt = post.EditedAt ?? post.CreationDate
-			});
+			//the author's server's own history (Pleroma's, Akkoma's) holds the version we had, and the edits we missed
+			if (note.FormerRepresentations.Count > 0)
+				post.Revisions = note.FormerRepresentations.ToList();
+			else
+				post.Revisions.Add(new PostRevision
+				{
+					Title = post.Title,
+					SpoilerText = post.SpoilerText,
+					ContentHtml = post.ContentHtml,
+					HasContentWarning = post.HasContentWarning,
+					EditedAt = post.EditedAt ?? post.CreationDate
+				});
 			if (post.Revisions.Count > MaxRevisions)
 				post.Revisions.RemoveRange(0, post.Revisions.Count - MaxRevisions);
 

PrivaPub/Federation/Inbox/RemotePosts.cs

@@ -133,7 +133,8 @@ namespace PrivaPub.Federation.Inbox
 				AuthorGone = author.AccountState == AvatarAccountState.Deleted,
 				CreationDate = note.Published,
 				UpdateDate = note.Updated ?? note.Published,
-				EditedAt = note.Updated
+				EditedAt = note.Updated,
+				Revisions = note.FormerRepresentations.ToList()
 			};
 			await Episode(post, note, author, token);
 			return post;