feat(ntfy): 푸시 알림 서버 Phase 1 인프라 구축

- docker-compose.yml에 ntfy 서비스 추가 (포트 30750)
- ntfy/etc/server.yml 서버 설정 (인증 deny-all, 72h 캐시)
- ntfy/README.md 운영 매뉴얼

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

docker-compose.yml

@@ -481,6 +481,25 @@ services:
     networks:
       - tk-network
 
+  # =================================================================
+  # ntfy — 푸시 알림 서버
+  # =================================================================
+
+  ntfy:
+    image: binwiederhier/ntfy
+    container_name: tk-ntfy
+    restart: unless-stopped
+    command: serve
+    ports:
+      - "30750:80"
+    environment:
+      - TZ=Asia/Seoul
+    volumes:
+      - ./ntfy/etc:/etc/ntfy
+      - ntfy_cache:/var/cache/ntfy
+    networks:
+      - tk-network
+
   # =================================================================
   # AI Service — 맥미니로 이전됨 (~/docker/tk-ai-service/)
   # =================================================================
@@ -544,6 +563,7 @@ services:
       - tksafety-web
       - tksupport-web
       - tkeg-web
+      - ntfy
     networks:
       - tk-network
 
@@ -563,6 +583,7 @@ volumes:
     name: tkqc-package_uploads
   tkeg_postgres_data:
   tkeg_uploads:
+  ntfy_cache:
 networks:
   tk-network:
     driver: bridge