Use WriteFile instead of stream writing to files

api/account/register.go

@@ -3,6 +3,7 @@ package account
 import (
 	"crypto/rand"
 	"fmt"
+	"os"
 
 	"github.com/pagefaultgames/pokerogue-server/db"
 )
@@ -34,5 +35,10 @@ func Register(username, password string) error {
 		return fmt.Errorf("failed to add account record: %s", err)
 	}
 
+	err = os.MkdirAll(fmt.Sprintf("userdata/%x", uuid), 0755)
+	if err != nil && !os.IsExist(err) {
+		return fmt.Errorf(fmt.Sprintf("failed to create userdata folder: %s", err))
+	}
+
 	return nil
 }