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

frontend/modules/project-management/components/TaskCard.vue

@@ -20,12 +20,6 @@
                         name="mdi:flag-variant"
                         class="h-3.5 w-3.5 text-red-600"
                     />
-                    <Icon
-                        v-if="task.clientTicket"
-                        name="heroicons:user-circle"
-                        class="h-3.5 w-3.5 text-primary-500"
-                        :title="$t('clientTicket.linkedTooltip', { number: formatTicketNumber(task.clientTicket.number) })"
-                    />
                 </div>
                 <h4 class="line-clamp-2 text-sm font-semibold text-neutral-900">{{ task.title }}</h4>
             </div>
@@ -109,7 +103,6 @@
 
 <script setup lang="ts">
 import type { Task } from '~/modules/project-management/services/dto/task'
-import { formatTicketNumber } from '~/modules/client-portal/utils/ticket'
 
 const props = withDefaults(defineProps<{
     task: Task