sequenceDiagram
 autonumber
 participant User as 사용자 브라우저
 participant Website as Website 서버
 participant Queue as Queue Server
 participant Redis as Redis
 User->>Website: GET /?user_id={userId}
 Website->>Website: 쿠키에서 user-queue-{queue}-token 조회
 Website->>Queue: GET /api/v1/queue/allowed<br/>queue={queue}&user_id={userId}&token={token}
 Queue->>Queue: 토큰 유효성 검증
 Queue-->>Website: { allowed: true | false }
 alt 진입 허용됨
 Website-->>User: index.html 반환
 else 진입 불가
 Website-->>User: 302 Redirect<br/>/waiting-room?user_id={userId}&redirect_url={websiteUrl}
 User->>Queue: GET /waiting-room
 Queue->>Queue: 쿠키 토큰 재검증
 alt 유효한 토큰 있음
 Queue-->>User: 302 Redirect to Website
 else 유효한 토큰 없음
 Queue->>Redis: ZADD users:queue:{queue}:wait<br/>member=userId, score=timestamp
 Redis-->>Queue: 등록 결과
 Queue->>Redis: ZRANK users:queue:{queue}:wait userId
 Redis-->>Queue: 현재 순번
 Queue-->>User: waiting-room.html 반환
 end
 loop 1초마다 순번 조회
 User->>Queue: GET /api/v1/queue/rank<br/>queue={queue}&user_id={userId}
 Queue->>Redis: ZRANK users:queue:{queue}:wait userId
 Redis-->>Queue: rank
 Queue-->>User: { rank: number }
 end
 par 스케줄러 자동 처리
 Queue->>Redis: ZPOPMIN users:queue:{queue}:wait
 Redis-->>Queue: 대기열 앞 사용자 목록
 Queue->>Redis: ZADD users:queue:{queue}:proceed
 end
 User->>Queue: GET /api/v1/queue/rank
 Queue->>Redis: ZRANK users:queue:{queue}:wait userId
 Redis-->>Queue: -1
 Queue-->>User: { rank: -1 }
 User->>Queue: GET /api/v1/queue/touch<br/>queue={queue}&user_id={userId}
 Queue->>Queue: SHA-256 토큰 생성
 Queue-->>User: Set-Cookie: user-queue-{queue}-token={token}
 User->>Website: GET /?user_id={userId}
 Website->>Queue: GET /api/v1/queue/allowed
 Queue-->>Website: { allowed: true }
 Website-->>User: index.html 반환
 end