Add functionality to manage account members: implement add and remove member events, update account repository methods, and integrate with trip details for participant management.

lib/blocs/account/account_event.dart

@@ -85,4 +85,32 @@ class CreateAccountWithMembers extends AccountEvent {
 
   @override
   List<Object?> get props => [account, members];
+}
+
+/// Event to add a member to an existing account.
+/// 
+/// This event is dispatched when a new member needs to be added to
+/// an account, typically when editing a trip and adding new participants.
+class AddMemberToAccount extends AccountEvent {
+  final String accountId;
+  final GroupMember member;
+
+  const AddMemberToAccount(this.accountId, this.member);
+
+  @override
+  List<Object?> get props => [accountId, member];
+}
+
+/// Event to remove a member from an existing account.
+/// 
+/// This event is dispatched when a member needs to be removed from
+/// an account, typically when editing a trip and removing participants.
+class RemoveMemberFromAccount extends AccountEvent {
+  final String accountId;
+  final String memberId;
+
+  const RemoveMemberFromAccount(this.accountId, this.memberId);
+
+  @override
+  List<Object?> get props => [accountId, memberId];
 }