complete story 4.2 with qa tests

app/Notifications/TimelineUpdateNotification.php

@@ -0,0 +1,72 @@
+<?php
+
+namespace App\Notifications;
+
+use App\Models\TimelineUpdate;
+use Illuminate\Bus\Queueable;
+use Illuminate\Contracts\Queue\ShouldQueue;
+use Illuminate\Notifications\Messages\MailMessage;
+use Illuminate\Notifications\Notification;
+
+class TimelineUpdateNotification extends Notification implements ShouldQueue
+{
+    use Queueable;
+
+    /**
+     * Create a new notification instance.
+     */
+    public function __construct(
+        public TimelineUpdate $timelineUpdate
+    ) {}
+
+    /**
+     * Get the notification's delivery channels.
+     *
+     * @return array<int, string>
+     */
+    public function via(object $notifiable): array
+    {
+        return ['mail'];
+    }
+
+    /**
+     * Get the mail representation of the notification.
+     */
+    public function toMail(object $notifiable): MailMessage
+    {
+        $locale = $notifiable->preferred_language ?? 'ar';
+
+        return (new MailMessage)
+            ->subject($this->getSubject($locale))
+            ->view('emails.timeline-update', [
+                'timelineUpdate' => $this->timelineUpdate,
+                'timeline' => $this->timelineUpdate->timeline,
+                'locale' => $locale,
+                'user' => $notifiable,
+            ]);
+    }
+
+    /**
+     * Get the subject based on locale.
+     */
+    private function getSubject(string $locale): string
+    {
+        return $locale === 'ar'
+            ? 'تحديث جديد على قضيتك'
+            : 'New Update on Your Case';
+    }
+
+    /**
+     * Get the array representation of the notification.
+     *
+     * @return array<string, mixed>
+     */
+    public function toArray(object $notifiable): array
+    {
+        return [
+            'type' => 'timeline_update',
+            'timeline_update_id' => $this->timelineUpdate->id,
+            'timeline_id' => $this->timelineUpdate->timeline_id,
+        ];
+    }
+}