fix: compare scheduler_type enum value, not enum object

BackendSchedulerType.KAI is an enum, not a string.
Use .value for comparison.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: vvnpn-nv

src/service/core/config/tests/test_configmap_loader_integration.py

@@ -217,7 +217,7 @@ def test_backend_list_from_snapshot(self):
         self.assertEqual(len(result), 1)
         self.assertEqual(result[0].name, 'test-be')
         self.assertEqual(
-            result[0].scheduler_settings.scheduler_type, 'kai')
+            result[0].scheduler_settings.scheduler_type.value, 'kai')
 
     def test_backend_names_from_snapshot(self):
         """Backend.list_names_from_db returns names from snapshot."""