비밀번호 재설정 중복 완료 요청 문제 수정

backend/internal/handler/common_test.go

@@ -21,6 +21,7 @@ type mockIdpProvider struct {
 	err             error
 	initiateLinkErr error
 	updateCalled    bool
+	updateCallCount int
 	updatedLoginID  string
 	updatedPassword string
 }
@@ -68,6 +69,7 @@ func (m *mockIdpProvider) VerifyPasswordResetToken(token string) (*domain.AuthIn
 
 func (m *mockIdpProvider) UpdateUserPassword(loginID, newPassword string, r *http.Request) error {
 	m.updateCalled = true
+	m.updateCallCount++
 	m.updatedLoginID = loginID
 	m.updatedPassword = newPassword
 	return m.err