Make optional API key environments nonblocking

errors.go

@@ -21,16 +21,20 @@ func mapPublicError(err error) error {
 		strings.TrimSpace(internalCapacityError.BackendID) != "" {
 		return &CapacityError{BackendID: internalCapacityError.BackendID}
 	}
+	publicErr := publicErrorFor(err)
 	var providerHTTPError *llm.ProviderHTTPError
 	if errors.As(err, &providerHTTPError) && providerHTTPError != nil {
-		return newGenerationError(
+		generationErr := newGenerationError(
 			providerHTTPError.StatusCode(),
 			providerHTTPError.ProviderCode(),
 			providerHTTPError.ProviderType(),
 			providerHTTPError.ProviderMessage(),
 		)
+		if publicErr != nil && !errors.Is(publicErr, ErrLLMGenerate) {
+			return fmt.Errorf("%w: %w", publicErr, generationErr)
+		}
+		return generationErr
 	}
-	publicErr := publicErrorFor(err)
 	if publicErr == nil {
 		return err
 	}