Merge pull request #4508 from wucm667/fix/model-not-found-transient-misclassification

fix: 临时账号耗尽时保留 503 错误分类

backend/internal/handler/no_account_error.go

@@ -38,11 +38,12 @@ type noAccountErrorClassification struct {
 // The classifier intentionally does not consume the original error: the
 // selection layer never tells us *why* the pool came up empty (rate-limited
 // vs. unsupported model are both wrapped as ErrNoAvailableAccounts). Instead
-// we re-check pool composition through DiagnoseModelAvailabilityForPlatform,
-// which only inspects model_mapping configuration and ignores transient
-// state. That guarantees a 404 is only returned when no operator action
-// short of editing the account's model_mapping could make this request
-// succeed.
+// we re-check pool composition through DiagnoseModelAvailabilityForPlatform.
+// Its dedicated database query considers only persistent eligibility
+// (active status + schedulable setting) and model_mapping, bypassing scheduler
+// snapshots and transient filters. That guarantees a 404 is only returned
+// when persistent account/group/model configuration must change before the
+// request can succeed.
 //
 // routingModel is the model name that account selection actually compared
 // against (i.e. after group-level dispatch mapping). displayModel is the

backend/internal/handler/no_account_error_test.go

@@ -154,6 +154,20 @@ func TestClassifyNoAccountError_HasModelSupport_KeepsRoutingMessageGenerationToC
 	require.False(t, cls.ModelNotFound)
 }
 
+func TestClassifyNoAccountError_ModelSupportedOnlyByRateLimitedAccount_Returns503(t *testing.T) {
+	c := newTestGinContextWithRequest()
+	// The diagnoser's configured-state lookup still sees the model-supporting
+	// account even though normal scheduling has excluded it during cooldown.
+	fd := &fakeDiagnoser{resp: service.ModelAvailabilityDiagnosis{HasAccountsInPool: true, HasModelSupport: true}}
+	apiKey := &service.APIKey{GroupID: ptrInt64(7)}
+
+	cls := classifyNoAccountErrorFromGin(c, fd, apiKey, "claude-opus-4-8", "claude-opus-4-8", service.PlatformAnthropic)
+
+	require.Equal(t, http.StatusServiceUnavailable, cls.Status)
+	require.Equal(t, "api_error", cls.ErrType)
+	require.False(t, cls.ModelNotFound, "temporary account cooldown must remain retryable")
+}
+
 func TestClassifyNoAccountError_NoAccountsInPool_Stays503(t *testing.T) {
 	c := newTestGinContextWithRequest()
 	fd := &fakeDiagnoser{resp: service.ModelAvailabilityDiagnosis{HasAccountsInPool: false, HasModelSupport: false}}