update controllers logic

app/Models/Invoice.php

@@ -14,12 +14,14 @@ class Invoice extends BaseModel
      * CI: useTimestamps = false because DB defaults/triggers manage created_at/updated_at.
      * In Laravel, keep timestamps OFF and let DB handle them.
      */
-    public $timestamps = true;
+    public $timestamps = false;
 
     protected $fillable = [
         'parent_id',
         'invoice_number',
         'total_amount',
+        'school_year',
+        'semester',
         'balance',
         'paid_amount',
         'has_discount',
@@ -27,11 +29,9 @@ class Invoice extends BaseModel
         'due_date',
         'status',
         'description',
-        'school_year',
         'created_at',
         'updated_at',
         'updated_by',
-        'semester',
     ];
 
     protected $casts = [