fix: scope inferred work-order tasks to the current work order

Prevent service-record inference from pulling tasks from other work orders
that share the same vehicle. This keeps task-service-context, service
reports, and related work-order widgets isolated to the selected nalog.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

backend/modules/fleet/tests/test_work_order_images_endpoint.py

@@ -26,7 +26,11 @@ from modules.fleet.models import (
 )
 from modules.task_management.models import Task, TaskWorkHoursTable
 from modules.fleet.tasks import build_monthly_archive_cached_task
-from modules.fleet.views import _build_monthly_servicer_report_rows, _calculate_daily_quantity_from_hours
+from modules.fleet.views import (
+    _build_monthly_servicer_report_rows,
+    _calculate_daily_quantity_from_hours,
+    _work_order_related_tasks_queryset,
+)
 
 
 def create_test_image(filename='test.jpg', size=(40, 40), color='red'):
@@ -236,6 +240,33 @@ class WorkOrderImagesEndpointTests(TestCase):
         self.assertIn('additional_costs_table', payload)
         self.assertEqual(payload['additional_costs_table']['total_for_payout'], '5.00')
 
+    def test_work_order_related_tasks_queryset_excludes_other_work_orders_for_same_vehicle(self):
+        other_work_order = WorkOrder.objects.create(
+            vehicle=self.vehicle,
+            creator=self.user,
+            display_code='MT160726',
+            purpose='kontrola',
+        )
+        other_task = Task.objects.create(
+            title='Drugi nalog isti stroj',
+            assigned_to=self.user,
+            vehicle=self.vehicle,
+            work_order=other_work_order,
+            scheduled_date=date(2033, 12, 25),
+        )
+        VehicleServiceRecord.objects.create(
+            vehicle=self.vehicle,
+            task=other_task,
+            performed_by=self.user,
+            description='Ne smije se pojaviti u prvom nalogu.',
+            service_title='Krivi nalog',
+        )
+
+        resolved_ids = list(_work_order_related_tasks_queryset(self.work_order).values_list('id', flat=True))
+
+        self.assertIn(self.task.pk, resolved_ids)
+        self.assertNotIn(other_task.pk, resolved_ids)
+
     def test_invoice_upload_immediately_appears_in_additional_costs_table(self):
         create_response = self.client.post(
             reverse('work-order-invoice-list'),