1. 문제 상황SSE(Server-Sent Events)를 사용해 실시간 알림을 발송하던 중 다음 예외가 발생했다.com.fasterxml.jackson.databind.JsonMappingException: could not initialize proxy [com.inconcert.domain.category.entity.Category#1] - no Session (through reference chain: com.inconcert.domain.post.dto.PostDTO["postCategory"]-> com.inconcert.domain.category.entity.PostCategory["category"]->com.inconcert.domain.category.entity.Category$..