feat(variety): 방송사 프리셋을 입력 빈도수 기반으로 변경

- GET /admin/variety/broadcasters: DB에서 빈도수 상위 10개 조회 (Redis 1시간 캐시)
- 일정 생성/수정 시 캐시 무효화
- 프론트엔드: 하드코딩 프리셋 제거, API에서 동적으로 로드

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/src/routes/admin/variety.js

@@ -5,12 +5,43 @@ import { badRequest, notFound, serverError } from '../../utils/error.js';
 import { logActivity } from '../../utils/log.js';
 
 const VARIETY_CATEGORY_ID = CATEGORY_IDS.VARIETY;
+const BROADCASTER_KEY = 'variety:broadcasters';
 
 /**
  * 예능 관련 관리자 라우트
  */
 export default async function varietyRoutes(fastify) {
-  const { db, meilisearch } = fastify;
+  const { db, meilisearch, redis } = fastify;
+
+  /**
+   * GET /api/admin/variety/broadcasters
+   * 자주 사용된 방송사/플랫폼 목록 (상위 10개)
+   */
+  fastify.get('/broadcasters', {
+    preHandler: [fastify.authenticate],
+  }, async () => {
+    // Redis에 캐시가 있으면 사용
+    const cached = await redis.get(BROADCASTER_KEY);
+    if (cached) {
+      return JSON.parse(cached);
+    }
+
+    // DB에서 빈도수 조회
+    const [rows] = await db.query(
+      `SELECT broadcaster, COUNT(*) as cnt
+       FROM schedule_variety
+       GROUP BY broadcaster
+       ORDER BY cnt DESC
+       LIMIT 10`
+    );
+
+    const broadcasters = rows.map(r => r.broadcaster);
+
+    // Redis 캐시 (1시간)
+    await redis.setex(BROADCASTER_KEY, 3600, JSON.stringify(broadcasters));
+
+    return broadcasters;
+  });
 
   /**
    * POST /api/admin/variety/schedule
@@ -96,6 +127,9 @@ export default async function varietyRoutes(fastify) {
         member_names: memberNames,
       });
 
+      // 방송사 캐시 무효화
+      await redis.del(BROADCASTER_KEY);
+
       logActivity(db, { actor: 'admin', action: 'create', category: 'schedule', targetType: 'variety_schedule', targetId: scheduleId, summary: `예능 일정 생성: ${title.trim()}` });
       return { success: true, scheduleId };
     } catch (err) {
@@ -181,6 +215,7 @@ export default async function varietyRoutes(fastify) {
       }
 
       await syncScheduleById(meilisearch, db, parseInt(id));
+      await redis.del(BROADCASTER_KEY);
       logActivity(db, { actor: 'admin', action: 'update', category: 'schedule', targetType: 'variety_schedule', targetId: parseInt(id), summary: `예능 일정 수정: ${title.trim()}` });
       return { success: true };
     } catch (err) {

frontend/src/api/admin/variety.js

@@ -23,3 +23,10 @@ export async function getVarietySchedule(id) {
 export async function updateVarietySchedule(id, formData) {
   return fetchFormData(`/admin/variety/schedule/${id}`, formData, 'PUT');
 }
+
+/**
+ * 자주 사용된 방송사/플랫폼 목록
+ */
+export async function getBroadcasters() {
+  return fetchAuthApi('/admin/variety/broadcasters');
+}

frontend/src/pages/pc/admin/schedules/edit/VarietyEditForm.jsx

@@ -11,12 +11,8 @@ import Toast from "@/components/common/Toast";
 import { useToast } from "@/hooks/common";
 import { useAdminAuth } from "@/hooks/pc/admin";
 import { getMembers } from "@/api/public/members";
-import { getVarietySchedule, updateVarietySchedule } from "@/api/admin/variety";
+import { getVarietySchedule, updateVarietySchedule, getBroadcasters } from "@/api/admin/variety";
 
-const broadcasterPresets = [
-  "KBS", "MBC", "SBS", "tvN", "JTBC",
-  "Mnet", "유튜브", "티빙", "웨이브", "쿠팡플레이",
-];
 
 /**
  * 예능 일정 수정 폼
@@ -41,6 +37,13 @@ function VarietyEditForm() {
     enabled: isAuthenticated && !!id,
   });
 
+  const { data: broadcasterPresets = [] } = useQuery({
+    queryKey: ["broadcasters"],
+    queryFn: getBroadcasters,
+    enabled: isAuthenticated,
+    staleTime: 5 * 60 * 1000,
+  });
+
   const [title, setTitle] = useState("");
   const [broadcaster, setBroadcaster] = useState("");
   const [date, setDate] = useState("");

frontend/src/pages/pc/admin/schedules/form/VarietyForm.jsx

@@ -10,7 +10,7 @@ import TimePicker from "@/components/pc/admin/common/TimePicker";
 import { useToast } from "@/hooks/common";
 import { useAdminAuth } from "@/hooks/pc/admin";
 import { getMembers } from "@/api/public/members";
-import { createVarietySchedule } from "@/api/admin/variety";
+import { createVarietySchedule, getBroadcasters } from "@/api/admin/variety";
 
 /**
  * 예능 일정 추가 폼
@@ -40,11 +40,13 @@ function VarietyForm() {
   const [selectedMemberIds, setSelectedMemberIds] = useState([]);
   const [saving, setSaving] = useState(false);
 
-  // 방송사 프리셋
-  const broadcasterPresets = [
-    "KBS", "MBC", "SBS", "tvN", "JTBC",
-    "Mnet", "유튜브", "티빙", "웨이브", "쿠팡플레이",
-  ];
+  // 자주 사용된 방송사 목록
+  const { data: broadcasterPresets = [] } = useQuery({
+    queryKey: ["broadcasters"],
+    queryFn: getBroadcasters,
+    enabled: isAuthenticated,
+    staleTime: 5 * 60 * 1000,
+  });
 
   // 멤버 토글
   const toggleMember = (memberId) => {