Refactor: Enforce type safety, fix close deadlock, implement assignee restrictions and notify admin fallbacks

app/Models/Contract.php

@@ -7,6 +7,9 @@ use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\BelongsTo;
 use Illuminate\Database\Eloquent\Relations\HasMany;
 
+use App\Enums\ContractType;
+use App\Enums\ContractStatus;
+
 #[Fillable(['product_id', 'customer_id', 'type', 'start_date', 'end_date', 'status', 'printed_at', 'signed_status'])]
 class Contract extends Model
 {
@@ -16,6 +19,8 @@ class Contract extends Model
             'start_date' => 'date',
             'end_date' => 'date',
             'printed_at' => 'date',
+            'type' => ContractType::class,
+            'status' => ContractStatus::class,
         ];
     }