Add exception error manager

Signed-off-by: Asai Neko <sugar@sne.moe>

service/auth/exchange.go

@@ -11,6 +11,8 @@ import (
 	"github.com/google/uuid"
 )
 
+const ()
+
 func Exchange(c *gin.Context) {
 	var exchangeReq struct {
 		ClientId    string `json:"client_id"`