fix: use exception instead of response in onBefore callback for duplicate driver check

The previous fix returned response()->error() directly from inside the
createRecordFromRequest onBefore callback. The trait checks for a
JsonResponse return and short-circuits correctly, but the outer
createRecord method then passed the JsonResponse object as $record
into the Driver resource serializer (line 245), causing:

  ErrorException: Undefined property: Illuminate\Http\JsonResponse::$id
  in DelegatesToResource.php

The correct approach is to throw a \Exception from within the callback,
which propagates out of createRecordFromRequest and is caught by the
existing catch (\Exception $e) block, which then returns
response()->error($e->getMessage()) — producing the correct 400 JSON
error response to the frontend.

Author: roncodes

server/src/Http/Controllers/Internal/v1/DriverController.php

@@ -141,7 +141,7 @@ function (&$request, &$input) {
                         if ($user) {
                             $existingDriver = Driver::where(['user_uuid' => $user->uuid, 'company_uuid' => session('company')])->first();
                             if ($existingDriver) {
-                                return response()->error('This user account already belongs to a driver.');
+                                throw new \Exception('This user account already belongs to a driver.');
                             }
                         }