feat: add iOS support and harden receipt scanning

app/ios/ScanReceipts/Features/Receipts/ShareSheet.swift

@@ -0,0 +1,20 @@
+import SwiftUI
+import UIKit
+
+/// Thin `UIViewControllerRepresentable` wrapper around `UIActivityViewController`,
+/// used by `ExportSheet` to hand an exported file off to Mail, Files,
+/// AirDrop, etc.
+struct ShareSheet: UIViewControllerRepresentable {
+    let activityItems: [Any]
+    var excludedActivityTypes: [UIActivity.ActivityType]?
+
+    func makeUIViewController(context: Context) -> UIActivityViewController {
+        let controller = UIActivityViewController(activityItems: activityItems, applicationActivities: nil)
+        controller.excludedActivityTypes = excludedActivityTypes
+        return controller
+    }
+
+    func updateUIViewController(_ uiViewController: UIActivityViewController, context: Context) {
+        // Nothing to update — the activity items are fixed for the sheet's lifetime.
+    }
+}