fix: ganti throw Exception di ActivityObserver dengan Filament Notification, guard creator null

app/Observers/ActivityObserver.php

@@ -5,6 +5,7 @@ namespace App\Observers;
 use App\Models\Activity;
 use App\Models\ActivityLog;
 use App\Services\NotificationService;
+use Filament\Notifications\Notification;
 use Illuminate\Support\Facades\Auth;
 
 class ActivityObserver
@@ -22,12 +23,18 @@ class ActivityObserver
             ];
 
             if (isset($allowed[$old]) && ! in_array($new, $allowed[$old])) {
-                throw new \Exception("Transisi status dari {$old} ke {$new} tidak diizinkan.");
+                Notification::make()->title('Transisi tidak diizinkan')
+                    ->body("Status tidak bisa diubah dari {$old} ke {$new}.")
+                    ->danger()->send();
+                $activity->status = $old;
+                return;
             }
 
-            // Wajib isi executed_at & execution_notes jika sudah approved dan mau ditandai selesai
             if ($new === 'approved' && $activity->wasChanged('executed_at') && empty($activity->execution_notes)) {
-                throw new \Exception('Catatan pelaksanaan wajib diisi.');
+                Notification::make()->title('Catatan pelaksanaan wajib diisi')
+                    ->danger()->send();
+                $activity->executed_at = null;
+                return;
             }
 
             ActivityLog::create([
@@ -44,7 +51,7 @@ class ActivityObserver
                     route('filament.admin.resources.activities.edit', $activity));
             }
 
-            if (in_array($new, ['approved', 'rejected'])) {
+            if (in_array($new, ['approved', 'rejected']) && $activity->creator) {
                 NotificationService::send(
                     $activity->creator,
                     $new === 'approved' ? 'Kegiatan Disetujui' : 'Kegiatan Ditolak',