Personas a remote post is addressed to see it, named or not

A remote post decided who here may see it by its Mention tags alone. A
followers-only post addressed in to or cc to a persona without naming
it (Akkoma's to[], or a GoToSocial edit that took the @name out while
the post stayed addressed to the persona) was hidden from that persona.
Such personas are now kept as silent mentions, as Mastodon does: they
see the post and it reaches their home, and no list shows them as
mentioned. An edit never narrows who a post was for.

The GoToSocial note that showed it is the first captured fixture
(Fixtures/gotosocial), and parses with its lone tag, to and cc.

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

PrivaPub.Tests/Federation/InboxScenarioTests.cs

@@ -263,6 +263,28 @@ namespace PrivaPub.Tests.Federation
 			Assert.Equal(alice.Id, mention.AccountId);
 		}
 
+		// GoToSocial kept a persona in cc after an edit took the @name out, and Akkoma addresses with to[] alone: the persona it
+		// is addressed to sees a followers-only post as a silent mention, which no list shows as a mention (found by the town)
+		[Fact]
+		public async Task A_followers_only_post_addressed_to_a_persona_without_naming_it_is_a_silent_mention()
+		{
+			var token = TestContext.Current.CancellationToken;
+			var alice = await LocalAvatar("alice");
+			var bob = new RemoteActor(_peer, "bob");
+			var create = PublicCreate(bob, default, alice.Uri);
+			create["object"]!["to"] = bob.Id + "/followers";
+			create["object"]!["cc"] = alice.Uri;
+
+			await Deliver(bob, "/human-centipede", create);
+
+			var post = await DB.Default.Find<Post>().Match(p => p.ActorURI == bob.Id).ExecuteSingleAsync(token);
+			Assert.Equal(PostVisibility.FollowersOnly, post.Visibility);
+			var mention = Assert.Single(post.Mentions);
+			Assert.True(mention.Silent);
+			Assert.Equal(alice.Id, mention.AccountId);
+			Assert.True(await PrivaPub.Domain.Privacy.VisibilityPolicy.CanSee(post, alice.Id, token));
+		}
+
 		[Fact]
 		public async Task A_suspended_domain_is_dropped_before_its_key_is_fetched()
 		{