refactor(client-portal) : remove client portal feature entirely

- drop ClientPortal module, ClientTicket entity, ROLE_CLIENT and all couplings (Task, TaskDocument, User, Notification) back to an internal-only model

- migration drops client_ticket / user_allowed_projects / related FK columns and removes leftover external client accounts (would otherwise be promoted to ROLE_USER)

- remove client-portal frontend module, admin tickets tab, user portal section, portal nav item and portal/clientTicket i18n keys

- fix directory nav icon (invalid mdi:contact-multiple-outline -> mdi:card-account-details-outline)

- add 'make sync-permissions' target, wire it into install/db-reset and the prod deploy script

config/modules.php

@@ -8,7 +8,6 @@ declare(strict_types=1);
  */
 
 use App\Module\Absence\AbsenceModule;
-use App\Module\ClientPortal\ClientPortalModule;
 use App\Module\Core\CoreModule;
 use App\Module\Directory\DirectoryModule;
 use App\Module\Integration\IntegrationModule;
@@ -26,5 +25,4 @@ return [
     MailModule::class,
     IntegrationModule::class,
     ReportingModule::class,
-    ClientPortalModule::class,
 ];