feat: Refactor bank account handling in billing and staff modules

- Introduced new bank account entities: BusinessBankAccount and StaffBankAccount.
- Updated bank account adapter to handle new entities.
- Removed legacy BankAccount entity and its adapter.
- Implemented use case for fetching bank accounts in billing repository.
- Updated BillingBloc and BillingState to include bank accounts.
- Refactored PaymentMethodCard to display bank account information.
- Adjusted actions widget layout for better UI consistency.
- Updated staff bank account repository and use cases to utilize new entity structure.
- Ensured all references to bank accounts in the codebase are updated to the new structure.

apps/mobile/packages/domain/lib/src/adapters/financial/bank_account/bank_account_adapter.dart

@@ -0,0 +1,21 @@
+import '../../../entities/financial/bank_account/business_bank_account.dart';
+
+/// Adapter for [BusinessBankAccount] to map data layer values to domain entity.
+class BusinessBankAccountAdapter {
+  /// Maps primitive values to [BusinessBankAccount].
+  static BusinessBankAccount fromPrimitives({
+    required String id,
+    required String bank,
+    required String last4,
+    required bool isPrimary,
+    DateTime? expiryTime,
+  }) {
+    return BusinessBankAccount(
+      id: id,
+      bankName: bank,
+      last4: last4,
+      isPrimary: isPrimary,
+      expiryTime: expiryTime,
+    );
+  }
+}

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

@@ -1,9 +1,9 @@
-import '../../entities/profile/bank_account.dart';
+import '../../entities/financial/bank_account/staff_bank_account.dart';
 
-/// Adapter for [BankAccount] to map data layer values to domain entity.
+/// Adapter for [StaffBankAccount] to map data layer values to domain entity.
 class BankAccountAdapter {
-  /// Maps primitive values to [BankAccount].
-  static BankAccount fromPrimitives({
+  /// Maps primitive values to [StaffBankAccount].
+  static StaffBankAccount fromPrimitives({
     required String id,
     required String userId,
     required String bankName,
@@ -13,7 +13,7 @@ class BankAccountAdapter {
     String? sortCode,
     bool? isPrimary,
   }) {
-    return BankAccount(
+    return StaffBankAccount(
       id: id,
       userId: userId,
       bankName: bankName,
@@ -26,25 +26,25 @@ class BankAccountAdapter {
     );
   }
 
-  static BankAccountType _stringToType(String? value) {
-    if (value == null) return BankAccountType.checking;
+  static StaffBankAccountType _stringToType(String? value) {
+    if (value == null) return StaffBankAccountType.checking;
     try {
       // Assuming backend enum names match or are uppercase
-      return BankAccountType.values.firstWhere(
-        (e) => e.name.toLowerCase() == value.toLowerCase(),
-        orElse: () => BankAccountType.other,
+      return StaffBankAccountType.values.firstWhere(
+        (StaffBankAccountType e) => e.name.toLowerCase() == value.toLowerCase(),
+        orElse: () => StaffBankAccountType.other,
       );
     } catch (_) {
-      return BankAccountType.other;
+      return StaffBankAccountType.other;
     }
   }
 
   /// Converts domain type to string for backend.
-  static String typeToString(BankAccountType type) {
+  static String typeToString(StaffBankAccountType type) {
     switch (type) {
-      case BankAccountType.checking:
+      case StaffBankAccountType.checking:
         return 'CHECKING';
-      case BankAccountType.savings:
+      case StaffBankAccountType.savings:
         return 'SAVINGS';
       default:
         return 'CHECKING';

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

@@ -0,0 +1,27 @@
+import 'package:equatable/equatable.dart';
+
+/// Abstract base class for all types of bank accounts.
+abstract class BankAccount extends Equatable {
+  /// Creates a [BankAccount].
+  const BankAccount({
+    required this.id,
+    required this.bankName,
+    required this.isPrimary,
+    this.last4,
+  });
+
+  /// Unique identifier.
+  final String id;
+
+  /// Name of the bank or provider.
+  final String bankName;
+
+  /// Whether this is the primary payment method.
+  final bool isPrimary;
+
+  /// Last 4 digits of the account/card.
+  final String? last4;
+
+  @override
+  List<Object?> get props => <Object?>[id, bankName, isPrimary, last4];
+}

apps/mobile/packages/domain/lib/src/entities/financial/bank_account/business_bank_account.dart

@@ -0,0 +1,26 @@
+import 'bank_account.dart';
+
+/// Domain model representing a business bank account or payment method.
+class BusinessBankAccount extends BankAccount {
+  /// Creates a [BusinessBankAccount].
+  const BusinessBankAccount({
+    required super.id,
+    required super.bankName,
+    required String last4,
+    required super.isPrimary,
+    this.expiryTime,
+  }) : super(last4: last4);
+
+  /// Expiration date if applicable.
+  final DateTime? expiryTime;
+
+  @override
+  List<Object?> get props => <Object?>[
+    ...super.props,
+    expiryTime,
+  ];
+
+  /// Getter for non-nullable last4 in Business context.
+  @override
+  String get last4 => super.last4!;
+}

apps/mobile/packages/domain/lib/src/entities/financial/bank_account/staff_bank_account.dart

@@ -0,0 +1,48 @@
+import 'bank_account.dart';
+
+/// Type of staff bank account.
+enum StaffBankAccountType {
+  /// Checking account.
+  checking,
+
+  /// Savings account.
+  savings,
+
+  /// Other type.
+  other,
+}
+
+/// Domain entity representing a staff's bank account.
+class StaffBankAccount extends BankAccount {
+  /// Creates a [StaffBankAccount].
+  const StaffBankAccount({
+    required super.id,
+    required this.userId,
+    required super.bankName,
+    required this.accountNumber,
+    required this.accountName,
+    required super.isPrimary,
+    super.last4,
+    this.sortCode,
+    this.type = StaffBankAccountType.checking,
+  });
+
+  /// User identifier.
+  final String userId;
+
+  /// Full account number.
+  final String accountNumber;
+
+  /// Name of the account holder.
+  final String accountName;
+
+  /// Sort code (optional).
+  final String? sortCode;
+
+  /// Account type.
+  final StaffBankAccountType type;
+
+  @override
+  List<Object?> get props =>
+      <Object?>[...super.props, userId, accountNumber, accountName, sortCode, type];
+}

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

@@ -1,53 +0,0 @@
-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 {
-
-  const BankAccount({
-    required this.id,
-    required this.userId,
-    required this.bankName,
-    required this.accountNumber,
-    required this.accountName,
-    this.sortCode,
-    this.type = BankAccountType.checking,
-    this.isPrimary = false,
-    this.last4,
-  });
-  /// Unique identifier.
-  final String id;
-
-  /// The [User] owning the account.
-  final String userId;
-
-  /// Name of the bank.
-  final String bankName;
-
-  /// Account number.
-  final String accountNumber;
-
-  /// Name on the account.
-  final String accountName;
-
-  /// 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, type, isPrimary, last4];
-}