fix(backend): handle relay-delivered Announce activities correctly

Relay Announce activities now use the target note URI instead of the
Announce URI for federation allowlist checks, dedup locking, and
existence lookups. Notes delivered via relay are published directly to
the notes stream without creating a renote.

Closes #11056

Author: sinoru

CHANGELOG.md

@@ -13,6 +13,7 @@
 - Fix: `/api-doc` にアクセスできない問題を修正
 - Fix: support `alsoKnownAs` from remote actors as either array or unwrapped singleton
 - Fix: ローカルに存在しないリモートアカウントに対するアカウント削除リクエストを受信した際に、そのユーザーを新規作成して削除する挙動を修正
+- Fix: リレー経由で届いたノートがRenoteとして表示される問題を修正
 
 ## 2026.3.2
 

packages/backend/src/core/RelayService.ts

@@ -91,13 +91,27 @@ export class RelayService {
 		return JSON.stringify(result);
 	}
 
+	@bindThis
+	public async getAcceptedRelays(): Promise<MiRelay[]> {
+		return this.relaysCache.fetch(() => this.relaysRepository.findBy({
+			status: 'accepted',
+		}));
+	}
+
+	@bindThis
+	public async isRelayActor(actor: { inbox: string | null; sharedInbox: string | null }): Promise<boolean> {
+		const relays = await this.getAcceptedRelays();
+		return relays.some(relay =>
+			(actor.inbox != null && relay.inbox === actor.inbox)
+			|| (actor.sharedInbox != null && relay.inbox === actor.sharedInbox),
+		);
+	}
+
 	@bindThis
 	public async deliverToRelays(user: { id: MiUser['id']; host: null; }, activity: any): Promise<void> {
 		if (activity == null) return;
 
-		const relays = await this.relaysCache.fetch(() => this.relaysRepository.findBy({
-			status: 'accepted',
-		}));
+		const relays = await this.getAcceptedRelays();
 		if (relays.length === 0) return;
 
 		const copy = deepClone(activity);

packages/backend/src/core/activitypub/ApInboxService.ts

@@ -302,12 +302,14 @@ export class ApInboxService {
 
 	@bindThis
 	private async announceNote(actor: MiRemoteUser, activity: IAnnounce, target: IPost, resolver?: Resolver): Promise<string | void> {
-		const uri = getApId(activity);
-
 		if (actor.isSuspended) {
 			return;
 		}
 
+		// リレーからのAnnounceかチェック
+		const fromRelay = await this.relayService.isRelayActor(actor);
+		const uri = getApId(fromRelay ? target : activity);
+
 		// アナウンス先が許可されているかチェック
 		if (!this.utilityService.isFederationAllowedUri(uri)) return;
 
@@ -336,6 +338,14 @@ export class ApInboxService {
 				throw err;
 			}
 
+			// リレーからのAnnounceはリノートを作成せず、ノートを直接公開する
+			if (fromRelay) {
+				this.logger.info(`Publishing relay-delivered note: ${uri}`);
+				const noteObj = await this.noteEntityService.pack(renote, null, { skipHide: true, withReactionAndUserPairCache: true });
+				this.globalEventService.publishNotesStream(noteObj);
+				return;
+			}
+
 			if (!await this.noteEntityService.isVisibleForMe(renote, actor.id)) {
 				return 'skip: invalid actor for this activity';
 			}