A community announces back to its author's own server

Lemmy keeps its user's post in a community pending until the community announces it back. A community hosted here
announced only to its followers, so a post from a server where nobody follows the community stayed pending there; the
author's own server (its shared inbox) now gets the announces too. INTEROP records, confirmed live, why Lemmy refuses
our Flags (an Application reporter, no `to`, an array object). FEDERATION.md's custom emoji line is put back before the
replies paragraph.

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

docs/ROADMAP.md

@@ -661,7 +661,8 @@ it, raw where it doesn't.
     ban of a persona refuses its posts there and shows as `blocked_by`), featured, moderators, `Warn`, `Resolve`;
   - votes in and out; link posts; flairs; `Feed` actors; community polls; post `Move`;
   - the outbound shape Lemmy requires;
-  - communities we host announce to the author's own instance too;
+  - communities we host announce to the author's own instance too: **done 2026-10-06** (its server's shared inbox,
+    whether anyone there follows the community or not: Lemmy keeps its user's post pending until it is announced back);
   - Flags from a `Service`-typed reporter actor.
 - **GoToSocial interaction policies** (**done 2026-10-05**, `InteractionApprovals`): stored and shown as
   `interaction_policy`; `ReplyRequest`/`LikeRequest`/`AnnounceRequest` where approval is needed; `Accept{result}`