Improved authentication; added fallbacks to 3D; cleaner dashboard charts

frontend/components/navigation/Monitoring.tsx

@@ -1,4 +1,4 @@
-import React from 'react';
+import React, { useState } from 'react';
 import Image from 'next/image';
 
 interface MonitoringProps {
@@ -7,6 +7,8 @@ interface MonitoringProps {
 }
 
 const Monitoring: React.FC<MonitoringProps> = ({ onClose }) => {
+  const [objectImageError, setObjectImageError] = useState(false);
+
   return (
     <div className="w-full"> 
       <div className="bg-[rgb(22,24,36)] rounded-[12px] p-4 space-y-4"> 
@@ -26,18 +28,26 @@ const Monitoring: React.FC<MonitoringProps> = ({ onClose }) => {
  
         <div className="bg-[rgb(158,168,183)] rounded-lg p-3 h-[200px] flex items-center justify-center">
           <div className="w-full h-full bg-gray-300 rounded flex items-center justify-center">
-            <Image 
-              src="/images/test_image.png"
-              alt="Object Model"
-              width={200}
-              height={200}
-              className="max-w-full max-h-full object-contain"
-              style={{ height: 'auto' }}
-              onError={(e) => {
-                const target = e.target as HTMLImageElement;
-                target.style.display = 'none';
-              }}
-            />
+            {objectImageError ? (
+              <div className="text-center p-4">
+                <div className="text-gray-600 text-sm font-semibold mb-2">
+                  Предпросмотр 3D недоступен
+                </div>
+                <div className="text-gray-500 text-xs">
+                  Изображение модели не найдено
+                </div>
+              </div>
+            ) : (
+              <Image 
+                src="/images/test_image.png"
+                alt="Object Model"
+                width={200}
+                height={200}
+                className="max-w-full max-h-full object-contain"
+                style={{ height: 'auto' }}
+                onError={() => setObjectImageError(true)}
+              />
+            )}
           </div>
         </div>