fix gateway loopback validation chains

apps/api/internal/clients/simulation.go

@@ -34,7 +34,8 @@ func (c SimulationClient) Run(ctx context.Context, request Request) (Response, e
 		}
 	}
 	responseFinishedAt := time.Now()
-	if profile == "retryable_failure" {
+	switch profile {
+	case "retryable_failure":
 		return Response{}, &ClientError{
 			Code:               "server_error",
 			Message:            "simulated retryable failure",
@@ -44,8 +45,27 @@ func (c SimulationClient) Run(ctx context.Context, request Request) (Response, e
 			ResponseDurationMS: responseDurationMS(responseStartedAt, responseFinishedAt),
 			Retryable:          true,
 		}
-	}
-	if profile == "fatal_failure" || profile == "non_retryable_failure" {
+	case "rate_limit", "overloaded":
+		return Response{}, &ClientError{
+			Code:               profile,
+			Message:            "simulated " + profile,
+			RequestID:          "simulated-request",
+			ResponseStartedAt:  responseStartedAt,
+			ResponseFinishedAt: responseFinishedAt,
+			ResponseDurationMS: responseDurationMS(responseStartedAt, responseFinishedAt),
+			Retryable:          true,
+		}
+	case "invalid_api_key":
+		return Response{}, &ClientError{
+			Code:               "invalid_api_key",
+			Message:            "simulated invalid_api_key",
+			RequestID:          "simulated-request",
+			ResponseStartedAt:  responseStartedAt,
+			ResponseFinishedAt: responseFinishedAt,
+			ResponseDurationMS: responseDurationMS(responseStartedAt, responseFinishedAt),
+			Retryable:          false,
+		}
+	case "fatal_failure", "non_retryable_failure":
 		return Response{}, &ClientError{
 			Code:               "bad_request",
 			Message:            "simulated non-retryable failure",
@@ -184,7 +204,7 @@ func simulatedVideoData(request Request) []any {
 }
 
 func simulatedUsage(request Request) Usage {
-	if request.ModelType == "chat" || request.Kind == "responses" {
+	if request.ModelType == "chat" || request.ModelType == "text_generate" || request.Kind == "responses" {
 		return Usage{InputTokens: 12, OutputTokens: 8, TotalTokens: 20}
 	}
 	return Usage{}