feat(ntfy): Phase 2 — sendPushToUsers() ntfy 연동 + 구독 관리 UI

- ntfy_subscriptions 테이블 마이그레이션 추가
- ntfySender.js 유틸 (ntfy HTTP POST 래퍼)
- sendPushToUsers() ntfy 우선 분기 (ntfy 구독자 → ntfy, 나머지 → Web Push)
- ntfy subscribe/unsubscribe/status API 엔드포인트
- notification-bell.js ntfy 토글 버튼 + 앱 설정 안내 모달
- docker-compose system1-api에 NTFY 환경변수 추가

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

system1-factory/api/models/notificationModel.js

@@ -24,19 +24,44 @@ function getWebPush() {
   return vapidConfigured ? webpush : null;
 }
 
-// Push 전송 헬퍼 — 알림 생성 후 호출
+// Push 전송 헬퍼 — 알림 생성 후 호출 (ntfy 우선, 나머지 Web Push)
 async function sendPushToUsers(userIds, payload) {
-  const wp = getWebPush();
-  if (!wp) return;
+  const pushModel = require('./pushSubscriptionModel');
+  const { sendNtfy } = require('../utils/ntfySender');
 
   try {
-    const pushModel = require('./pushSubscriptionModel');
-    const subscriptions = userIds && userIds.length > 0
-      ? await pushModel.getByUserIds(userIds)
-      : await pushModel.getAll(); // broadcast
+    // 1) ntfy 구독자 분리
+    const ntfyUserIds = userIds && userIds.length > 0
+      ? await pushModel.getNtfyUserIds(userIds)
+      : await pushModel.getAllNtfyUserIds();
+
+    const ntfySet = new Set(ntfyUserIds);
+
+    // 2) ntfy 병렬 발송
+    if (ntfyUserIds.length > 0) {
+      await Promise.allSettled(
+        ntfyUserIds.map(uid =>
+          sendNtfy(uid, { title: payload.title, body: payload.body, url: payload.url })
+        )
+      );
+    }
+
+    // 3) Web Push — ntfy 구독자 제외
+    const wp = getWebPush();
+    if (!wp) return;
+
+    let subscriptions;
+    if (userIds && userIds.length > 0) {
+      const webPushUserIds = userIds.filter(id => !ntfySet.has(id));
+      subscriptions = webPushUserIds.length > 0
+        ? await pushModel.getByUserIds(webPushUserIds)
+        : [];
+    } else {
+      // broadcast: 전체 구독 가져온 뒤 ntfy 사용자 제외
+      subscriptions = (await pushModel.getAll()).filter(s => !ntfySet.has(s.user_id));
+    }
 
     const payloadStr = JSON.stringify(payload);
-
     for (const sub of subscriptions) {
       try {
         await wp.sendNotification({
@@ -44,7 +69,6 @@ async function sendPushToUsers(userIds, payload) {
           keys: { p256dh: sub.p256dh, auth: sub.auth }
         }, payloadStr);
       } catch (err) {
-        // 만료 구독 (410 Gone, 404 Not Found) 자동 정리
         if (err.statusCode === 410 || err.statusCode === 404) {
           await pushModel.deleteByEndpoint(sub.endpoint).catch(() => {});
         }