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/Models/Post/Post.cs

@@ -111,6 +111,8 @@ namespace PrivaPub.Models.Post
 		public string AccountId { get; set; }
 		public string Handle { get; set; }
 		public bool IsLocal { get; set; }
+		//addressed in to or cc without a Mention tag (Mastodon's silent mention): may see the post, but the post does not name it
+		public bool Silent { get; set; }
 	}
 
 	public class PostRevision