feat: add notifications module with bell UI, event listeners, and cleanup job

In-app notification system with topbar bell icon, dropdown panel,
mark-as-read/dismiss actions, and scheduled cleanup of old read
notifications. Includes event listeners for user.created and
user.deleted events, authorization policy, and full test coverage.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

modules/notifications/lib/Module/Notifications/Handler/NotificationCleanupJobHandler.php

@@ -0,0 +1,43 @@
+<?php
+
+namespace MintyPHP\Module\Notifications\Handler;
+
+use MintyPHP\Module\Notifications\Service\NotificationService;
+use MintyPHP\Service\Scheduler\Handler\ScheduledJobHandlerInterface;
+
+class NotificationCleanupJobHandler implements ScheduledJobHandlerInterface
+{
+    public function __construct(private readonly NotificationService $notificationService)
+    {
+    }
+
+    public function definition(): array
+    {
+        return [
+            'label' => 'Notification cleanup',
+            'description' => 'Purges read notifications older than 90 days',
+            'default_enabled' => 1,
+            'default_timezone' => defined('APP_TIMEZONE') ? (string) APP_TIMEZONE : 'UTC',
+            'default_schedule_type' => 'daily',
+            'default_schedule_interval' => 1,
+            'default_schedule_time' => '04:00',
+            'default_schedule_weekdays_csv' => null,
+            'default_catchup_once' => 1,
+            'allowed_schedule_types' => ['daily', 'weekly'],
+        ];
+    }
+
+    public function execute(?int $actorUserId): array
+    {
+        $deleted = $this->notificationService->purgeOldRead(90);
+
+        return [
+            'status' => 'success',
+            'error_code' => null,
+            'error_message' => null,
+            'result' => [
+                'deleted_count' => $deleted,
+            ],
+        ];
+    }
+}