fix(barcode-scanner): resolve scan() after cleanup in windowed mode on iOS

Reorder operations in metadataOutput so that dismantleCamera() and
webview restoration run before invoke.resolve(). Previously, resolve()
was called first and destroy() immediately after, which restored
webView.isOpaque before the IPC response reached JavaScript — causing
the scan() promise to never settle in windowed mode.

Author: afadil

plugins/barcode-scanner/ios/Sources/BarcodeScannerPlugin.swift

@@ -122,17 +122,19 @@ class BarcodeScannerPlugin: Plugin, AVCaptureMetadataOutputObjectsDelegate {
         jsObject["content"] = found.stringValue
       }
 
-      invoke?.resolve(jsObject)
-      // Stop processing further detections immediately to prevent
-      // duplicate resolve calls during the delay window below.
+      // Stop scanning and clean up camera and webview state before
+      // resolving. In windowed mode, restoring webView.isOpaque after
+      // resolve() prevents the IPC response from reaching JavaScript.
       self.isScanning = false
-      // Delay destroy so the IPC response reaches the JS layer before
-      // the webview properties (isOpaque, backgroundColor) are restored.
-      // Without this, the promise returned by scan() never resolves in
-      // windowed mode on iOS.
-      DispatchQueue.main.asyncAfter(deadline: .now() + 0.3) { [weak self] in
-        self?.destroy()
+      dismantleCamera()
+      if windowed {
+        let backgroundColor = previousBackgroundColor ?? UIColor.white
+        webView.isOpaque = true
+        webView.backgroundColor = backgroundColor
+        webView.scrollView.backgroundColor = backgroundColor
       }
+      invoke?.resolve(jsObject)
+      invoke = nil
 
     }
   }