feat(vereinfacht): sync linked member after user email/link changes

- SyncLinkedMemberAfterUserChange on update, create_user, update_user,
  admin_set_password, link_oidc_id, register_with_rauthy

lib/accounts/user.ex

@@ -118,6 +118,8 @@ defmodule Mv.Accounts.User do
       change Mv.EmailSync.Changes.SyncUserEmailToMember do
         where [changing(:email)]
       end
+
+      change Mv.Vereinfacht.Changes.SyncLinkedMemberAfterUserChange
     end
 
     create :create_user do
@@ -145,6 +147,8 @@ defmodule Mv.Accounts.User do
 
       # Sync user email to member when linking (User → Member)
       change Mv.EmailSync.Changes.SyncUserEmailToMember
+
+      change Mv.Vereinfacht.Changes.SyncLinkedMemberAfterUserChange
     end
 
     update :update_user do
@@ -178,6 +182,8 @@ defmodule Mv.Accounts.User do
       change Mv.EmailSync.Changes.SyncUserEmailToMember do
         where any([changing(:email), changing(:member)])
       end
+
+      change Mv.Vereinfacht.Changes.SyncLinkedMemberAfterUserChange
     end
 
     # Internal update used only by SystemActor/bootstrap and tests to assign role to system user.
@@ -211,6 +217,8 @@ defmodule Mv.Accounts.User do
       change Mv.EmailSync.Changes.SyncUserEmailToMember do
         where [changing(:email)]
       end
+
+      change Mv.Vereinfacht.Changes.SyncLinkedMemberAfterUserChange
     end
 
     # Action to link an OIDC account to an existing password-only user
@@ -248,6 +256,8 @@ defmodule Mv.Accounts.User do
       change Mv.EmailSync.Changes.SyncUserEmailToMember do
         where [changing(:email)]
       end
+
+      change Mv.Vereinfacht.Changes.SyncLinkedMemberAfterUserChange
     end
 
     read :get_by_subject do
@@ -328,6 +338,8 @@ defmodule Mv.Accounts.User do
       # Sync user email to member when linking (User → Member)
       change Mv.EmailSync.Changes.SyncUserEmailToMember
 
+      change Mv.Vereinfacht.Changes.SyncLinkedMemberAfterUserChange
+
       # Sync role from OIDC groups (e.g. admin group → Admin role) after user is created/updated
       change fn changeset, _ctx ->
         user_info = Ash.Changeset.get_argument(changeset, :user_info)