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';