feat(client-portal) : phase 3 — ticket notifications

LST-69 (3.2) phase 3. Wires the existing notification system to client-ticket
events (the bell/useNotifications/endpoints already existed).

- Notification.relatedTicket (ManyToOne ClientTicketInterface, SET NULL) +
  additive migration + notification:read group.
- NotifierInterface::notify() gains a backward-compatible optional
  relatedTicket param (existing callers unchanged).
- ClientTicketNumberProcessor (POST): notifies all ROLE_ADMIN users
  (ticket_created), tolerant try/catch after flush. ClientTicketStatusProcessor
  (PATCH): notifies submittedBy on status change (ticket_status_changed).
- Front: notification DTO relatedTicket; NotificationBell navigates to /admin
  (admin) or /portal (client) on ticket notifications.

180 tests green (178 + 2), nuxt build passes, cs-fixer clean.

migrations/Version20260621130000.php

@@ -0,0 +1,41 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DoctrineMigrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+/**
+ * Client portal — phase 3: link notifications to client tickets (additive).
+ *
+ * - Adds notification.related_ticket_id (FK client_ticket, SET NULL) plus its index,
+ *   so a notification can deep-link to the ticket it concerns without breaking the
+ *   existing task-based notifications (column is nullable).
+ *
+ * Lowercase SQL columns; FK/index names mirror Doctrine's generated identifiers.
+ * down() reverses.
+ */
+final class Version20260621130000 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return 'Client portal phase 3: notification.related_ticket_id link to client_ticket (additive)';
+    }
+
+    public function up(Schema $schema): void
+    {
+        $this->addSql('ALTER TABLE notification ADD related_ticket_id INT DEFAULT NULL');
+        $this->addSql('ALTER TABLE notification ADD CONSTRAINT FK_BF5476CA98F144DB FOREIGN KEY (related_ticket_id) REFERENCES client_ticket (id) ON DELETE SET NULL NOT DEFERRABLE');
+        $this->addSql('CREATE INDEX idx_notification_related_ticket ON notification (related_ticket_id)');
+        $this->addSql("COMMENT ON COLUMN notification.related_ticket_id IS 'Ticket client lie a la notification (FK client_ticket, SET NULL). null = notification non liee a un ticket.'");
+    }
+
+    public function down(Schema $schema): void
+    {
+        $this->addSql('ALTER TABLE notification DROP CONSTRAINT FK_BF5476CA98F144DB');
+        $this->addSql('DROP INDEX idx_notification_related_ticket');
+        $this->addSql('ALTER TABLE notification DROP related_ticket_id');
+    }
+}