added new restriction and fixed button dowload

src/components/BarcodeScanner.tsx

@@ -19,7 +19,6 @@ export default function BarcodeScanner({ onScan }: BarcodeScannerProps) {
     let zxingReader: BrowserMultiFormatReader | null = null;
     let detector: any = null;
 
-    /** 🚀 Intentar usar BarcodeDetector API (moderno) */
     const startBarcodeDetector = async () => {
       const supported = "BarcodeDetector" in window;
       if (!supported) {
@@ -100,13 +99,10 @@ export default function BarcodeScanner({ onScan }: BarcodeScannerProps) {
           return;
         }
 
-        // 🔍 Intentar encontrar la cámara trasera
         const backCamera =
-          devices.find((d) =>
-            d.label.toLowerCase().includes("back")
-          ) || devices.find((d) =>
-            d.label.toLowerCase().includes("rear")
-          ) || devices[devices.length - 1]; // fallback
+          devices.find((d) => d.label.toLowerCase().includes("back")) ||
+          devices.find((d) => d.label.toLowerCase().includes("rear")) ||
+          devices[devices.length - 1];
 
         const selectedDeviceId = backCamera.deviceId;
 
@@ -136,7 +132,6 @@ export default function BarcodeScanner({ onScan }: BarcodeScannerProps) {
 
     startBarcodeDetector();
 
-
     return () => {
       if (animationFrame) cancelAnimationFrame(animationFrame);
       if (stream) stream.getTracks().forEach((t) => t.stop());