fix(mobile): remove back button on MarketPage and fix transfer row overflow

- MarketPage: add automaticallyImplyLeading: false (tab-level page)
- TransferPage: wrap maskedContact in Flexible to prevent RIGHT OVERFLOW

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/genex-mobile/lib/features/coupons/presentation/pages/market_page.dart

@@ -38,6 +38,7 @@ class _MarketPageState extends State<MarketPage>
   Widget build(BuildContext context) {
     return Scaffold(
       appBar: AppBar(
+        automaticallyImplyLeading: false,
         title: Text(context.t('market.title')),
         actions: [
           IconButton(

frontend/genex-mobile/lib/features/trading/presentation/pages/transfer_page.dart

@@ -268,10 +268,13 @@ class _TransferPageState extends State<TransferPage> {
                   const SizedBox(height: 2),
                   Row(
                     children: [
-                      Text(
+                      Flexible(
-                        recipient.maskedContact,
+                        child: Text(
-                        style: AppTypography.caption.copyWith(
+                          recipient.maskedContact,
-                          color: AppColors.textTertiary,
+                          overflow: TextOverflow.ellipsis,
+                          style: AppTypography.caption.copyWith(
+                            color: AppColors.textTertiary,
+                          ),
                         ),
                       ),
                       const SizedBox(width: 8),