Community actors name their moderators the way Lemmy reads them

attributedTo points at /wardens and postingRestrictedToMods reflects the
posting policy.

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

FEDERATION.md

@@ -52,7 +52,7 @@ A group is either a **community** or a **circle**.
   moderators only) and the group `Announce`s the whole activity, with `audience` set, to its followers. A new post is
   also announced as an object so Mastodon shows it. Updates and deletes of community content are announced too. A
   top-level post is a `Page` with a `name`. Members are counted at `/flock`; moderators are listed at `/wardens`, which
-  `attributedTo` does not yet point to. A mention of a community posts into it.
+  the actor's `attributedTo` points to, with `postingRestrictedToMods` as Lemmy expects. A mention of a community posts into it.
 - A **circle** is private. Its actor is not discoverable and every follow is a request. Its posts are addressed to the
   circle and its members collection, delivered to each member's own inbox and never announced. They are served only
   to a signed request from a member, or from the instance actor of a member's server; anyone else gets 404. A