fix: 补充测试桩缺失的接口方法

backend/internal/service/antigravity_rate_limit_test.go

@@ -38,6 +38,10 @@ func (s *stubAntigravityUpstream) Do(req *http.Request, proxyURL string, account
 	}, nil
 }
 
+func (s *stubAntigravityUpstream) DoWithTLS(req *http.Request, proxyURL string, accountID int64, accountConcurrency int, enableTLSFingerprint bool) (*http.Response, error) {
+	return s.Do(req, proxyURL, accountID, accountConcurrency)
+}
+
 type scopeLimitCall struct {
 	accountID int64
 	scope     AntigravityQuotaScope