feat: implement BankAccountAdapter for mapping data layer values to domain entity and refactor BankAccountRepositoryImpl for improved staff ID handling

apps/mobile/packages/domain/lib/src/adapters/profile/bank_account_adapter.dart

@@ -0,0 +1,53 @@
+import '../../entities/profile/bank_account.dart';
+
+/// Adapter for [BankAccount] to map data layer values to domain entity.
+class BankAccountAdapter {
+  /// Maps primitive values to [BankAccount].
+  static BankAccount fromPrimitives({
+    required String id,
+    required String userId,
+    required String bankName,
+    required String? type,
+    String? accountNumber,
+    String? last4,
+    String? sortCode,
+    bool? isPrimary,
+  }) {
+    return BankAccount(
+      id: id,
+      userId: userId,
+      bankName: bankName,
+      accountNumber: accountNumber ?? '',
+      accountName: '', // Not provided by backend
+      last4: last4,
+      sortCode: sortCode,
+      type: _stringToType(type),
+      isPrimary: isPrimary ?? false,
+    );
+  }
+
+  static BankAccountType _stringToType(String? value) {
+    if (value == null) return BankAccountType.checking;
+    try {
+      // Assuming backend enum names match or are uppercase
+      return BankAccountType.values.firstWhere(
+        (e) => e.name.toLowerCase() == value.toLowerCase(),
+        orElse: () => BankAccountType.other,
+      );
+    } catch (_) {
+      return BankAccountType.other;
+    }
+  }
+
+  /// Converts domain type to string for backend.
+  static String typeToString(BankAccountType type) {
+    switch (type) {
+      case BankAccountType.checking:
+        return 'CHECKING';
+      case BankAccountType.savings:
+        return 'SAVINGS';
+      default:
+        return 'CHECKING';
+    }
+  }
+}