Add user validation in updateGR method to ensure scanned_by exists for the given plant

app/Http/Controllers/PdfController.php

@@ -5,6 +5,7 @@ namespace App\Http\Controllers;
 use App\Models\GrMaster;
 use App\Models\Item;
 use App\Models\Plant;
+use App\Models\User;
 use Illuminate\Http\Request;
 use Illuminate\Support\Facades\Response;
 use Illuminate\Support\Facades\Storage;
@@ -91,6 +92,17 @@ class PdfController extends Controller
             ], 400);
         }
 
+        $user = User::where('plant_id', $plantId)
+            ->where('name', $data['scanned_by'])
+            ->first();
+
+        if (!$user) {
+            return response()->json([
+                'status_code' => 'ERROR',
+                'status_description' => "'{$data['scanned_by']}' not found for plant {$data['plant_code']}!"
+            ], 404);
+        }
+
         $itemCodes = array_column($data['item_codes'], 'item_code');
 
         $duplicateItemCodes = array_unique(array_diff_assoc($itemCodes, array_unique($itemCodes)));