=== [1] refresh token 하나 확보 ===
  토큰 길이: 811
  jti: 8e7e3ee2-0dc8-573d-58ec-d12651a50b9c
  sid: BvFiB01Rntz1FcLdf7zG4BNt

=== [2] 같은 refresh token 으로 동시에 5회 갱신 ===
  요청 1: HTTP 400  {"error":"invalid_grant","error_description":"Maximum allowed refresh token reuse exceeded"}
  요청 2: HTTP 400  {"error":"invalid_grant","error_description":"Session doesn't have required client"}
  요청 3: HTTP 400  {"error":"invalid_grant","error_description":"Session doesn't have required client"}
  요청 4: HTTP 400  {"error":"invalid_grant","error_description":"Session doesn't have required client"}
  요청 5: HTTP 200  {"access_token":"...(발급됨)