diff --git a/app/firebase/functions/src/account/account.ts b/app/firebase/functions/src/account/account.ts
index 7e25121..0d1a6f2 100644
--- a/app/firebase/functions/src/account/account.ts
+++ b/app/firebase/functions/src/account/account.ts
@@ -147,6 +147,14 @@ function primaryPatch(user: Data, fandomId: string, cooldownDays: number, now: n
  * - `users/{uid}/memberships/{id}` — 「가입 또는 생성한 행성/성운」 목록(명세 §2.58)의 원천.
  * - `memberCount` 는 같은 트랜잭션에서 올린다 — 전환 조건(B-10)이 이 값을 읽는다.
  */
+/**
+ * 가입 약관(`termsAgreedAt`, [fnSignupConsent]) 없이 행성 · 성운 멤버가 되지 않게 막는다.
+ * 앱은 약관 화면부터 보내지만(app_router 게이트) 서버도 같은 기준을 지킨다 — 10/6 실기기 판정.
+ */
+function requireTerms(user: Data): void {
+  if (!user?.termsAgreedAt) fail(ERR.permissionDenied, '이용 약관에 동의한 뒤 가입할 수 있습니다.');
+}
+
 function writeJoin(tx: Transaction, uid: string, fandomId: string, fandom: Data): void {
   const db = getFirestore();
   const memberNo = Number(fandom?.memberSeq ?? fandom?.memberCount ?? 0) + 1;
@@ -199,6 +207,7 @@ export const fnNebulaCreate = onCall(async (req) => {
     const [todaySnap, nameSnap, userSnap] = await Promise.all([
       tx.get(todayRef), tx.get(nameRef), tx.get(userRef),
     ]);
+    requireTerms(userSnap.data());
     if (todaySnap.exists) fail(ERR.nebulaDailyLimit, '이미 오늘 성운을 생성하셨습니다.');
     if (nameSnap.exists) fail(ERR.fandomNameTaken, '이미 사용중인 이름입니다.');
     const { patch } = primaryPatch(userSnap.data(), fandom.id, policy.primaryCooldownDays, now);
@@ -243,6 +252,7 @@ export const fnFandomJoin = onCall(async (req) => {
     ]);
     if (!fandomSnap.exists) fail(ERR.permissionDenied, '행성을 찾을 수 없습니다.');
     if (memberSnap.exists) return { fandomId, joined: false };
+    requireTerms(userSnap.data());
     writeJoin(tx, uid, fandomId, fandomSnap.data());
     // 원장 S20(확인 전 유지 기준) — 창립자가 혼자 떠나 탄생 권한자가 빈 성운은 다음 가입자가 이어받는다.
     if (fandomSnap.get('stage') === 0 && !fandomSnap.get('founderUid')) {
diff --git a/app/firebase/functions/src/core/names.ts b/app/firebase/functions/src/core/names.ts
index f1acde0..27a7c97 100644
--- a/app/firebase/functions/src/core/names.ts
+++ b/app/firebase/functions/src/core/names.ts
@@ -11,3 +11,20 @@ export function publicNameOf(user: { get(field: string): unknown } | null | unde
   const v = typeof raw === 'string' ? raw.trim() : '';
   return v.length === 0 || v.includes('@') ? PUBLIC_NAME_FALLBACK : v;
 }
+
+/**
+ * 다국어 값 — 문자열이거나 언어별 지도(`{ko, en, …}`, 운영 Quest 제목 등 설계서 §2.8).
+ * 지도면 `locale`(`users/{uid}.locale`, 예 `zh-CN`) → 그 언어 코드 → ko → en → 아무 값.
+ * 앱 `SnapshotReader.textOr` 와 같은 계산. 알림 문구에 지도를 그대로 넣으면 「[object Object]」가 된다.
+ */
+export function localizedText(value: unknown, locale?: unknown): string {
+  if (typeof value === 'string') return value;
+  if (!value || typeof value !== 'object') return '';
+  const map = value as Record<string, unknown>;
+  const tag = typeof locale === 'string' ? locale : '';
+  for (const k of [tag, tag.split('-')[0], 'ko', 'en']) {
+    const v = k ? map[k] : undefined;
+    if (typeof v === 'string' && v) return v;
+  }
+  return Object.values(map).find((v): v is string => typeof v === 'string' && v.length > 0) ?? '';
+}
diff --git a/app/firebase/functions/src/notify/inbox.ts b/app/firebase/functions/src/notify/inbox.ts
index 3c06ed5..3c406f1 100644
--- a/app/firebase/functions/src/notify/inbox.ts
+++ b/app/firebase/functions/src/notify/inbox.ts
@@ -2,6 +2,7 @@ import { FieldValue, getFirestore } from 'firebase-admin/firestore';
 import { onDocumentCreated, onDocumentUpdated, onDocumentWritten } from 'firebase-functions/v2/firestore';
 import { logger } from 'firebase-functions';
 
+import { localizedText } from '../core/names.js';
 import { PUSH_CATEGORIES, sendUserPush, type UserPushOutcome } from './push.js';
 
 /**
@@ -99,8 +100,9 @@ export async function notifyQuestDone(
   const count = typeof after.count === 'number' ? after.count : 0;
   if (count < 1) return false;
   if (before && before.dayKey === after.dayKey && (before.count as number | undefined ?? 0) >= count) return false;
-  const quest = await getFirestore().doc(`quests/${questId}`).get();
-  const title = (quest.get('title') as string | undefined) ?? '';
+  const db = getFirestore();
+  const [quest, user] = await Promise.all([db.doc(`quests/${questId}`).get(), db.doc(`users/${uid}`).get()]);
+  const title = localizedText(quest.get('title'), user.get('locale'));
   return notifyOnce(uid, `quest_${questId}_${String(after.dayKey)}_${count}`, {
     eventType: 'quest', type: 'essential',
     title: `[${title}] 퀘스트를 완료했어요!`, source: '퀘스트',
diff --git a/app/firebase/functions/test/inbox.test.ts b/app/firebase/functions/test/inbox.test.ts
index 6e066c4..e7ef6d3 100644
--- a/app/firebase/functions/test/inbox.test.ts
+++ b/app/firebase/functions/test/inbox.test.ts
@@ -67,3 +67,14 @@ it('퀘스트 완료는 횟수가 오른 때만 본인에게, 상세 경로를 
   expect(quest[0]!.title).toBe('[만보기] 퀘스트를 완료했어요!');
   expect(quest[0]!.targetPath).toBe('quests/test-inbox-quest');
 });
+
+it('운영 Quest 의 다국어 제목은 사용자 언어(없으면 ko)로 푼다', async () => {
+  const db = getFirestore();
+  await db.doc('quests/test-inbox-quest').set({ title: { ko: '신곡 스트리밍', en: 'Stream the single' } });
+  await db.doc(`users/${B}`).set({ locale: 'en' });
+  await notifyQuestDone(A, 'test-inbox-quest', undefined, { dayKey: '2026-10-06', count: 1 });
+  await notifyQuestDone(B, 'test-inbox-quest', undefined, { dayKey: '2026-10-06', count: 1 });
+  const titles = async (uid: string) => (await inbox(uid)).filter((n) => n.eventType === 'quest').map((n) => n.title);
+  expect(await titles(A)).toContain('[신곡 스트리밍] 퀘스트를 완료했어요!');
+  expect(await titles(B)).toEqual(['[Stream the single] 퀘스트를 완료했어요!']);
+});
diff --git a/app/firebase/functions/test/planet_create.test.ts b/app/firebase/functions/test/planet_create.test.ts
index 2466b03..c760427 100644
--- a/app/firebase/functions/test/planet_create.test.ts
+++ b/app/firebase/functions/test/planet_create.test.ts
@@ -1,4 +1,4 @@
-import { afterAll, afterEach, beforeAll, describe, expect, it } from 'vitest';
+import { afterAll, afterEach, beforeAll, beforeEach, describe, expect, it } from 'vitest';
 import { FieldValue, getFirestore, Timestamp } from 'firebase-admin/firestore';
 
 import { bootAdmin, shutdownAdmin, wipeUser } from './support.js';
@@ -36,9 +36,14 @@ const user = async (uid = UID) => (await db().doc(`users/${uid}`).get()).data()
 const fandom = async (id: string) => (await db().doc(`fandoms/${id}`).get()).data() ?? {};
 
 beforeAll(() => { bootAdmin(); });
+// 가입 · 성운 생성은 약관 동의(`termsAgreedAt`)가 있어야 한다 — 시험 계정은 동의를 마친 상태로 시작한다.
+const agree = (uid: string) => db().doc(`users/${uid}`).set({ termsAgreedAt: Timestamp.now() }, { merge: true });
+beforeEach(async () => {
+  for (const uid of [UID, OTHER, 'test-planet-create-third']) await agree(uid);
+});
 afterAll(async () => { await shutdownAdmin(); });
 afterEach(async () => {
-  for (const uid of [UID, OTHER]) {
+  for (const uid of [UID, OTHER, 'test-planet-create-third']) {
     await wipeUser(uid);
     await db().recursiveDelete(db().collection(`users/${uid}/nebulaCreates`));
     await db().recursiveDelete(db().collection(`users/${uid}/memberships`));
@@ -64,6 +69,7 @@ describe('성운 생성', () => {
 
   it('대표 변경 30일 대기 중이면 성운 · 멤버십만 만들고 대표는 그대로 둔다(C-15)', async () => {
     await db().doc(`users/${UID}`).set({
+      termsAgreedAt: Timestamp.now(),
       primaryFandomId: 'old', fandomId: 'old', primaryChangedAt: Timestamp.fromMillis(Date.now() - 86_400_000),
     });
     const { fandomId, primaryChanged } = await call(fnNebulaCreate, { name: 'Cooldown' });
@@ -106,6 +112,14 @@ describe('가입 · 탈퇴 · 대표 팬덤', () => {
     expect((await user()).fandomIds).toEqual([id]);
   });
 
+  it('약관에 동의하지 않은 계정은 가입 · 성운 생성을 거부한다', async () => {
+    const { fandomId } = await call(fnNebulaCreate, { name: 'Terms Gate' });
+    await db().doc(`users/${OTHER}`).set({ termsAgreedAt: FieldValue.delete() }, { merge: true });
+    expect(await codeOf(() => call(fnFandomJoin, { fandomId }, OTHER))).toBe('E-PERM-01');
+    expect(await codeOf(() => call(fnNebulaCreate, { name: 'Terms Gate Two' }, OTHER))).toBe('E-PERM-01');
+    expect((await fandom(fandomId as string)).memberCount).toBe(1);
+  });
+
   it('없는 팬덤 가입 · 가입하지 않은 팬덤을 대표로 지정은 거부한다', async () => {
     expect(await codeOf(() => call(fnFandomJoin, { fandomId: 'missing-fandom' }))).toBe('E-PERM-01');
     const { fandomId } = await call(fnNebulaCreate, { name: 'NotMine' }, OTHER);
diff --git a/app/lib/app.dart b/app/lib/app.dart
index 91103b7..1419f68 100644
--- a/app/lib/app.dart
+++ b/app/lib/app.dart
@@ -194,7 +194,14 @@ class _FancakeAppState extends State<FancakeApp> with WidgetsBindingObserver {
       ..showSnackBar(
         SnackBar(
           behavior: SnackBarBehavior.floating,
-          content: Text(notice.title.isEmpty ? notice.body : notice.title),
+          // action 이 있으면 기본으로 남아 있으므로(Flutter 3.29+) 시간이 지나면 닫히게 한다.
+          persist: false,
+          duration: const Duration(seconds: 4),
+          content: Text(
+            [notice.title, notice.body].where((s) => s.isNotEmpty).join('\n'),
+            maxLines: 3,
+            overflow: TextOverflow.ellipsis,
+          ),
           action: SnackBarAction(
             label: (_messengerKey.currentContext ?? context).l10n.commonView,
             onPressed: () => _openFromPush(notice),