feat(attachments): refactor attachment management to use attachable pivot table and update related models and tests

app/Domains/Attachable/Models/Attachment.php

@@ -6,12 +6,10 @@ use App\Domains\Attachable\Enums\AttachmentType;
 use Illuminate\Database\Eloquent\Attributes\Fillable;
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
-use Illuminate\Database\Eloquent\Relations\MorphTo;
+use Illuminate\Database\Eloquent\Relations\HasMany;
 use Illuminate\Support\Str;
 
 #[Fillable([
-    'attachable_type',
-    'attachable_id',
     'key',
     'path',
     'filename',
@@ -38,17 +36,16 @@ class Attachment extends Model
     protected function casts(): array
     {
         return [
-            'attachable_id' => 'integer',
             'type' => AttachmentType::class,
             'size' => 'integer',
         ];
     }
 
     /**
-     * @return MorphTo<Model, $this>
+     * @return HasMany<AttachableAttachment, $this>
      */
-    public function attachable(): MorphTo
+    public function attachables(): HasMany
     {
-        return $this->morphTo();
+        return $this->hasMany(AttachableAttachment::class, 'attachment_id');
     }
 }