fix(billing): 默认关闭 OpenAI 长上下文计费

backend/internal/handler/admin/account_handler.go

@@ -1303,6 +1303,10 @@ func (h *AccountHandler) ApplyOAuthCredentials(c *gin.Context) {
 		response.ErrorFrom(c, infraerrors.BadRequest("NOT_OAUTH", "cannot apply oauth credentials to non-OAuth account"))
 		return
 	}
+	if err := service.ValidateOpenAILongContextBillingExtra(existing.Platform, req.Extra); err != nil {
+		response.ErrorFrom(c, err)
+		return
+	}
 
 	updatedAccount, err := h.adminService.UpdateAccount(ctx, accountID, &service.UpdateAccountInput{
 		Type:        req.Type,

backend/internal/handler/admin/account_handler_long_context_billing_test.go

@@ -8,6 +8,7 @@ import (
 	"testing"
 
 	infraerrors "github.com/Wei-Shaw/sub2api/internal/pkg/errors"
+	"github.com/Wei-Shaw/sub2api/internal/service"
 	"github.com/gin-gonic/gin"
 	"github.com/stretchr/testify/require"
 )
@@ -112,6 +113,35 @@ func TestAccountCreateBoundaryDoesNotApplyOpenAIValidationToOtherPlatforms(t *te
 	require.Equal(t, http.StatusOK, recorder.Code)
 }
 
+func TestApplyOAuthCredentialsRejectsMalformedOpenAILongContextBillingBeforeMutation(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	stub := newStubAdminService()
+	stub.getAccountResult = &service.Account{
+		ID:       1,
+		Platform: service.PlatformOpenAI,
+		Type:     service.AccountTypeOAuth,
+	}
+	handler := NewAccountHandler(stub, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil, nil)
+	router := gin.New()
+	router.POST("/accounts/:id/apply-oauth-credentials", handler.ApplyOAuthCredentials)
+	recorder := httptest.NewRecorder()
+	request := httptest.NewRequest(http.MethodPost, "/accounts/1/apply-oauth-credentials", bytes.NewBufferString(
+		`{"type":"oauth","credentials":{"access_token":"new-token"},"extra":{"openai_long_context_billing_enabled":"true"}}`,
+	))
+	request.Header.Set("Content-Type", "application/json")
+
+	router.ServeHTTP(recorder, request)
+
+	require.Equal(t, http.StatusBadRequest, recorder.Code)
+	var responseBody struct {
+		Reason string `json:"reason"`
+	}
+	require.NoError(t, json.Unmarshal(recorder.Body.Bytes(), &responseBody))
+	require.Equal(t, "OPENAI_LONG_CONTEXT_BILLING_INVALID", responseBody.Reason)
+	require.Zero(t, stub.updateAccountCalls)
+	require.Zero(t, stub.updateAccountExtraCalls)
+}
+
 func TestOpenAIOAuthCodexPATBoundaryRejectsMalformedOpenAILongContextBillingValueBeforeTokenValidation(t *testing.T) {
 	gin.SetMode(gin.TestMode)
 	handler := NewOpenAIOAuthHandler(nil, newStubAdminService(), nil)

backend/internal/handler/admin/admin_service_stub_test.go

@@ -33,6 +33,9 @@ type stubAdminService struct {
 	createSparkShadowErr                error
 	updateAccountErr                    error
 	bulkUpdateAccountErr                error
+	getAccountResult                    *service.Account
+	updateAccountCalls                  int
+	updateAccountExtraCalls             int
 	checkMixedErr                       error
 	lastMixedCheck                      struct {
 		accountID int64
@@ -388,6 +391,9 @@ func (s *stubAdminService) ListOpenAISchedulableAccountsForSchedulerScore(_ cont
 }
 
 func (s *stubAdminService) GetAccount(ctx context.Context, id int64) (*service.Account, error) {
+	if s.getAccountResult != nil {
+		return s.getAccountResult, nil
+	}
 	account := service.Account{ID: id, Name: "account", Status: service.StatusActive}
 	return &account, nil
 }
@@ -413,6 +419,7 @@ func (s *stubAdminService) CreateAccount(ctx context.Context, input *service.Cre
 }
 
 func (s *stubAdminService) UpdateAccount(ctx context.Context, id int64, input *service.UpdateAccountInput) (*service.Account, error) {
+	s.updateAccountCalls++
 	if s.updateAccountErr != nil {
 		return nil, s.updateAccountErr
 	}
@@ -421,6 +428,7 @@ func (s *stubAdminService) UpdateAccount(ctx context.Context, id int64, input *s
 }
 
 func (s *stubAdminService) UpdateAccountExtra(ctx context.Context, id int64, updates map[string]any) error {
+	s.updateAccountExtraCalls++
 	return nil
 }