P7: FEP-268d searchableBy decides what search finds

A remote account's searchableBy, and a post's own, outrank indexable in status search: Public lets anyone find a
public post, the author's followers only those who follow it, anything else nobody but those it already reaches
(their own, named, favourited, bookmarked or boosted posts). Read on actors and posts, kept through edits; PrivaPub
does not emit it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012CzABvBkbcFqoHdmi8b9WB

PrivaPub/Federation/Actors/RemoteActorService.cs

@@ -236,6 +236,7 @@ namespace PrivaPub.Federation.Actors
 				.Modify(a => a.MovedToURL, Origin.Of(actor.MovedTo) == default ? default : actor.MovedTo)
 				.Modify(a => a.ModeratorsURL, Origin.Same(actor.Moderators, actor.Id) ? actor.Moderators : default)
 				.Modify(a => a.Flairs, actor.Flairs)
+				.Modify(a => a.SearchableBy, actor.SearchableBy)
 				.Modify(a => a.AlsoKnownAs, actor.AlsoKnownAs)
 				.Modify(a => a.Published, actor.Published)
 				.Modify(a => a.Emojis, actor.Emojis)