fix(test): update _FailingConfigService.set_value() to match scoped signature

Update the test double to accept the scope keyword argument added by
master's scoped config changes, and pass project_root=None to avoid
auto-discovery in test environments.

ISSUES CLOSED: #993

features/steps/tdd_server_connect_atomic_writes_steps.py

@@ -23,7 +23,7 @@ from unittest.mock import patch
 from behave import given, then, when
 from behave.runner import Context
 
-from cleveragents.application.services.config_service import ConfigService
+from cleveragents.application.services.config_service import ConfigScope, ConfigService
 from cleveragents.infrastructure.events.reactive import ReactiveEventBus
 from cleveragents.infrastructure.events.types import EventType
 
@@ -62,11 +62,14 @@ class _FailingConfigService(ConfigService):
             config_dir=config_dir,
             config_path=config_path,
             event_bus=event_bus,
+            project_root=None,
         )
         self._fail_on_call = fail_on_call_number
         self._call_count = 0
 
-    def set_value(self, key: str, value: Any) -> None:
+    def set_value(
+        self, key: str, value: Any, *, scope: ConfigScope | None = None
+    ) -> None:
         """Override set_value to fail on a specific call number."""
         self._call_count += 1
         if self._call_count == self._fail_on_call:
@@ -74,7 +77,7 @@ class _FailingConfigService(ConfigService):
                 f"Simulated disk failure on set_value call #{self._call_count} "
                 f"(key={key!r})"
             )
-        super().set_value(key, value)
+        super().set_value(key, value, scope=scope)
 
 
 # ---------------------------------------------------------------------------
@@ -123,6 +126,7 @@ def step_pre_existing_config(context: Context) -> None:
     svc = ConfigService(
         config_dir=context.atomic_config_dir,
         config_path=context.atomic_config_path,
+        project_root=None,
     )
     svc.set_value("server.url", _ORIGINAL_URL)
     svc.set_value("server.namespace", _ORIGINAL_NAMESPACE)