fix(wallet-address): display receive address in EIP-55 checksummed form

lib/screens/settings_wallet_address/settings_wallet_address_page.dart

@@ -6,13 +6,16 @@ import 'package:realunit_wallet/packages/wallet/payment_uri.dart';
 import 'package:realunit_wallet/screens/receive/widgets/qr_address_widget.dart';
 import 'package:realunit_wallet/setup/di.dart';
 import 'package:realunit_wallet/styles/colors.dart';
+import 'package:web3dart/web3dart.dart';
 
 class SettingsWalletAddressPage extends StatelessWidget {
   const SettingsWalletAddressPage({super.key});
 
   @override
   Widget build(BuildContext context) {
-    final walletAddress = getIt<AppStore>().primaryAddress;
+    // Display the receive address in its EIP-55 checksummed form — the
+    // canonical representation that lets the user verify it by checksum.
+    final walletAddress = EthereumAddress.fromHex(getIt<AppStore>().primaryAddress).hexEip55;
 
     return Scaffold(
       appBar: AppBar(

test/screens/settings_wallet_address/settings_wallet_address_page_test.dart

@@ -42,5 +42,16 @@ void main() {
         findsOne,
       );
     });
+
+    testWidgets('displays the address in EIP-55 checksummed form', (tester) async {
+      await tester.pumpApp(const SettingsWalletAddressPage());
+
+      // The mocked primaryAddress is all-lowercase; the screen must render and
+      // encode the checksummed (EIP-55) form in both the text and the QR uri.
+      const checksummed = '0x938115B533a0b746428361760A6972dfd06D984a';
+      final qr = tester.widget<QRAddressWidget>(find.byType(QRAddressWidget));
+      expect(qr.subtitle, checksummed);
+      expect(qr.uri, contains(checksummed));
+    });
   });
 }