fix(mobile-app): fetch wallet address from server API instead of local storage

The wallet address displayed in long-press mode was incorrectly showing
another user's address from local storage cache. Now fetches the correct
address from the /me API endpoint for the currently logged-in user.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

frontend/mobile-app/lib/features/deposit/presentation/pages/deposit_usdt_page.dart

@@ -99,14 +99,28 @@ class _DepositUsdtPageState extends ConsumerState<DepositUsdtPage> {
           final walletService = ref.read(walletServiceProvider);
           final walletResponse = await walletService.getMyWallet();
 
-          // 获取真实钱包地址（用于隐藏模式）
-          final walletAddresses = await accountService.getWalletAddresses();
+          // 从服务器 API 获取真实钱包地址（用于隐藏模式）
+          // 不使用本地存储，避免显示其他用户的地址
+          String? kavaAddress;
+          try {
+            final meResponse = await accountService.getMe();
+            // 从 walletAddresses 中找到 KAVA 链的地址
+            for (final addr in meResponse.walletAddresses) {
+              if (addr.chainType.toUpperCase() == 'KAVA') {
+                kavaAddress = addr.address;
+                break;
+              }
+            }
+            debugPrint('[DepositUsdtPage] 从服务器获取 KAVA 地址: $kavaAddress');
+          } catch (e) {
+            debugPrint('[DepositUsdtPage] 获取钱包地址失败: $e');
+          }
 
           // 显示 USDT 可用余额
           if (mounted) {
             setState(() {
               _balance = walletResponse.balances.usdt.available.toStringAsFixed(2);
-              _realWalletAddress = walletAddresses?.kava;
+              _realWalletAddress = kavaAddress;
               _isLoading = false;
             });
           }