Move model observers onto attributes and tidy provider bindings.

Register observers with ObservedBy, bind the comment spam classifier, and keep AppServiceProvider focused on application wiring.

app/Models/ArtworkFeature.php

@@ -1,10 +1,14 @@
 <?php
+
 namespace App\Models;
 
+use App\Observers\ArtworkFeatureObserver;
+use Illuminate\Database\Eloquent\Attributes\ObservedBy;
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\BelongsTo;
 use Illuminate\Database\Eloquent\SoftDeletes;
 
+#[ObservedBy([ArtworkFeatureObserver::class])]
 class ArtworkFeature extends Model
 {
     use SoftDeletes;