feat: Implement bank account management feature with UI, BLoC integration, and repository setup

apps/mobile/packages/domain/lib/src/entities/profile/bank_account.dart

@@ -1,5 +1,12 @@
 import 'package:equatable/equatable.dart';
 
+/// Account type (Checking, Savings, etc).
+enum BankAccountType {
+  checking,
+  savings,
+  other,
+}
+
 /// Represents bank account details for payroll.
 class BankAccount extends Equatable {
 
@@ -10,6 +17,9 @@ class BankAccount extends Equatable {
     required this.accountNumber,
     required this.accountName,
     this.sortCode,
+    this.type = BankAccountType.checking,
+    this.isPrimary = false,
+    this.last4,
   });
   /// Unique identifier.
   final String id;
@@ -29,6 +39,15 @@ class BankAccount extends Equatable {
   /// Sort code (if applicable).
   final String? sortCode;
 
+  /// Type of account.
+  final BankAccountType type;
+
+  /// Whether this is the primary account.
+  final bool isPrimary;
+  
+  /// Last 4 digits.
+  final String? last4;
+
   @override
-  List<Object?> get props => <Object?>[id, userId, bankName, accountNumber, accountName, sortCode];
+  List<Object?> get props => <Object?>[id, userId, bankName, accountNumber, accountName, sortCode, type, isPrimary, last4];
 }