リモートのピン留め投稿取得対応 (#2798)

* Fetch featured

* Handle featured change

* Fix typo

src/remote/activitypub/kernel/remove/index.ts

@@ -0,0 +1,22 @@
+import { IRemoteUser } from '../../../../models/user';
+import { IRemove } from '../../type';
+import { resolveNote } from '../../models/note';
+import { removePinned } from '../../../../services/i/pin';
+
+export default async (actor: IRemoteUser, activity: IRemove): Promise<void> => {
+	if ('actor' in activity && actor.uri !== activity.actor) {
+		throw new Error('invalid actor');
+	}
+
+	if (activity.target == null) {
+		throw new Error('target is null');
+	}
+
+	if (activity.target === actor.featured) {
+		const note = await resolveNote(activity.object);
+		await removePinned(actor, note._id);
+		return;
+	}
+
+	throw new Error(`unknown target: ${activity.target}`);
+};