Pins across servers, both ways

An account elsewhere that pins or unpins one of its posts (Add or Remove on its `featured`) now shows those pins on its
profile here (`pinned=true`), in its order and its public posts only; a community's announce of a moderator's Add does
the same for the community. The `featured` collection itself is read with the account's counts, at most once a day, so
pins made before PrivaPub ever saw an account show too. Any other target (Smithereen's wall, a community's moderators)
is dropped. A persona's pin and unpin go to the post's audience as Add and Remove on /trophies, as Mastodon sends them.

Checked live against Mastodon (scenarios/pins.sh, 8 checks). The town's checker learnt three peer rules from the
village: Misskey and Sharkey keep a forwarded reply only with its author's LD signature (only Mastodon signs), they
count no renote by a bot, and Mastodon never sees a Lemmy vote on a post in a community. The village of 2026-10-05
checks clean, 2454 of 2454.

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

docs/ROADMAP.md

@@ -664,7 +664,8 @@ it, raw where it doesn't.
   - inbound `Move` with Mastodon's checks: **done 2026-10-05** (the old account shows `moved`, the personas' follows,
     lists, mutes and blocks move to the new one, owner decision; checked live against GoToSocial);
   - re-run WebFinger on a rename;
-  - inbound `Block`, plus `Add`/`Remove` of pins;
+  - inbound `Block`; `Add`/`Remove` of pins: **done 2026-10-05** (both ways, a community's pins too, the `featured`
+    collection read with an account's counts; checked live against Mastodon);
   - FEP-8fcf followers sync;
   - `indexable`/`discoverable`/`searchableBy`;
   - edit history from `formerRepresentations`;