fix: implementasi FilamentUser interface agar panel bisa diakses di production

- Tambah FilamentUser interface di User model
- Tambah canAccessPanel() method
- Tambah VoteObserver: broadcast notifikasi ke semua user saat vote baru
- Tambah NotificationService::toAll()
- Fix Vote model: auto-fill created_by via booted()
- Fix CashRecordObserver: fallback created_by untuk Vote

app/Observers/CashRecordObserver.php

@@ -47,7 +47,7 @@ class CashRecordObserver
                 'related_id' => $record->id,
                 'status'     => 'open',
                 'deadline'   => now()->addDays(3),
-                'created_by' => Auth::id(),
+                'created_by' => Auth::id() ?? $record->created_by,
             ]);
 
             NotificationService::toRole('ketua',

app/Observers/VoteObserver.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace App\Observers;
+
+use App\Models\Vote;
+use App\Services\NotificationService;
+
+class VoteObserver
+{
+    public function created(Vote $vote): void
+    {
+        NotificationService::toAll(
+            'Voting Baru Dibuat',
+            "Voting \"{$vote->title}\" telah dibuka. Silakan berikan suara Anda.",
+            'info',
+            route('filament.admin.resources.votes.index')
+        );
+    }
+}