fix: address code review findings

internal/yandex/client.go

@@ -7,6 +7,7 @@ import (
 	"math/rand"
 	"net/http"
 	"net/url"
+	"strings"
 	"sync"
 	"time"
 
@@ -269,8 +270,17 @@ func isRetryableError(err error) bool {
 	if err == nil {
 		return false
 	}
-	// Network-level errors are retryable
-	return true
+	// Check for HTTP status codes that are retryable (5xx errors)
+	apiErr, ok := err.(*APIError)
+	if ok {
+		return apiErr.Code >= 500 && apiErr.Code < 600
+	}
+	// Check for network errors
+	errStr := err.Error()
+	return strings.Contains(errStr, "timeout") ||
+		strings.Contains(errStr, "connection refused") ||
+		strings.Contains(errStr, "dial tcp") ||
+		strings.Contains(errStr, "context deadline exceeded")
 }
 
 // buildURL constructs a Yandex API URL with query parameters.