fix: add detectChanges for QR modal display

src/app/app.ts

@@ -396,6 +396,7 @@ export class App implements OnInit {
       // 4. Show QR modal
       this.showQrModal = true;
       this.paySuccess = false;
+      this.cdr.detectChanges();
 
       // Wait for DOM update, then render QR
       setTimeout(() => this.renderQR(codeUrl), 100);