Moves carry follows over; first DMs to Lemmy 0.19 and Mbin go as ChatMessage

Two owner decisions of 2026-10-05, both recorded in ROADMAP:
- After a verified Move the personas following the old account follow the new one, in the same lists, and a mute or
  block of the old account carries over, as Mastodon does it.
- A direct message to one account on a server whose NodeInfo names Lemmy before 1.0 or Mbin goes as a ChatMessage,
  the one place PrivaPub decides by a server's software (invariant 17). G-0008 is closed.

Mbin addresses its private messages to the recipient's profile page, so a Create addressed to a persona's /@name now
reaches the persona. Checked live: moves 8/8, Lemmy 0.19 30/30, Mbin 26/26 with messages both ways. The software
theory runs alone, since every test's peer shares 127.0.0.1.

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

PrivaPub.Tests/Federation/MoveTests.cs

@@ -1,6 +1,7 @@
 using MongoDB.Entities;
 
 using PrivaPub.Api.Mastodon.Mappers;
+using PrivaPub.Models.Social;
 using PrivaPub.Models.User;
 using PrivaPub.Tests.Support;
 
@@ -49,13 +50,23 @@ namespace PrivaPub.Tests.Federation
 		static Task<ForeignAvatar> Stored(RemoteActor actor) =>
 			DB.Default.Find<ForeignAvatar>().Match(a => a.ActorURI == actor.Id).ExecuteFirstAsync(TestContext.Current.CancellationToken);
 
+		// as Mastodon does it (owner decision 2026-10-05): the follow moves to the new account, in the same lists, and a mute
+		// or a block of the old account carries over
 		[Fact]
-		public async Task A_move_the_new_account_confirms_shows_the_old_account_moved_there()
+		public async Task A_move_the_new_account_confirms_moves_the_personas_follows_lists_mutes_and_blocks()
 		{
 			var token = TestContext.Current.CancellationToken;
 			var (_, alice) = await _harness.Persona("alice");
+			var (_, bob) = await _harness.Persona("bob");
 			var old = new RemoteActor(_harness.Peer, "old");
+			await _harness.Remote.GetActor(old.Id, refresh: true, token);
 			await Follows(alice.Id, old);
+			var oldAccount = await Stored(old);
+			var list = new PersonaList { AvatarId = alice.Id, Title = "friends" };
+			await DB.Default.SaveAsync(list, token);
+			await DB.Default.SaveAsync(new PersonaListMember { ListId = list.ID, AvatarId = alice.Id, AccountId = oldAccount.ID }, token);
+			await _harness.Relationships.Mute(alice, old.Id, oldAccount.ID, hideNotifications: true, duration: default, token);
+			await _harness.Relationships.Block(bob, old.Id, oldAccount.ID, token);
 			var target = Target("new", aliasOf: old);
 
 			await Move(old, old, target);
@@ -65,6 +76,14 @@ namespace PrivaPub.Tests.Federation
 			var account = await new MastodonMapper(_harness.Db, _harness.Local).Account(stored.ID, token);
 			Assert.Equal(target.Name, account.Moved?.Username);
 			Assert.Contains(_harness.Ledger.Of("in"), e => e.Activity == "Move" && e.Reason == "moved");
+			var newAccount = await Stored(target);
+			Assert.True(await DB.Default.Find<Following>().Match(f => f.AvatarId == alice.Id && f.TargetActorURI == target.Id).ExecuteAnyAsync(token));
+			Assert.False(await DB.Default.Find<Following>().Match(f => f.AvatarId == alice.Id && f.TargetActorURI == old.Id).ExecuteAnyAsync(token));
+			Assert.Contains(await _harness.Outgoing(target.Id + "/inbox"), a => a["type"]!.GetValue<string>() == "Follow");
+			Assert.Contains(await _harness.Outgoing(old.Id + "/inbox"), a => a["type"]!.GetValue<string>() == "Undo");
+			Assert.True(await DB.Default.Find<PersonaListMember>().Match(m => m.ListId == list.ID && m.AccountId == newAccount.ID).ExecuteAnyAsync(token));
+			Assert.True(await DB.Default.Find<Mute>().Match(m => m.AvatarId == alice.Id && m.TargetActorURI == target.Id).ExecuteAnyAsync(token));
+			Assert.True(await DB.Default.Find<Block>().Match(b => b.AvatarId == bob.Id && b.TargetActorURI == target.Id).ExecuteAnyAsync(token));
 		}
 
 		[Fact]