fix school year for all tables

app/Models/ClassModel.php

@@ -3,17 +3,25 @@
 namespace App\Models;
 
 use CodeIgniter\Model;
+use App\Models\Concerns\SchoolYearAutoFillTrait;
 
 class ClassModel extends Model
 {
+    use SchoolYearAutoFillTrait;
+
     protected $table = 'classes'; // The table name
     protected $primaryKey = 'id'; // The correct primary key for the classes table
 
+    // Fields that are allowed to be manipulated.
     protected $allowedFields = [
         'class_name', 
         'schedule', 
-        'capacity'
-    ]; // Fields that are allowed to be manipulated
+        'capacity',
+        'school_year',
+    ];
+    protected $validationRules = [
+        'school_year' => 'required|string|max_length[9]',
+    ];
 
     protected $useTimestamps = false;