fix(resource): update stale DETECTED→DISCOVERED scenario title in protocol methods

The devcontainer_handler_protocol_methods.feature file and its step
definitions still referenced the old ContainerLifecycleState.DETECTED
terminology. Update to DISCOVERED for consistency with specification.

ISSUES CLOSED: #7555

features/devcontainer_handler_protocol_methods.feature

@@ -124,10 +124,10 @@ Feature: DevcontainerHandler missing protocol methods
     Then dcproto the sandbox result should have strategy "snapshot"
     And dcproto the sandbox result should have a sandbox path
 
-  Scenario: dcproto create_sandbox activates container when in DETECTED state
+  Scenario: dcproto create_sandbox activates container when in DISCOVERED state
     Given dcproto a devcontainer handler
     And dcproto a devcontainer-instance resource with location "/ws/project"
-    And dcproto the container is in DETECTED state
+    And dcproto the container is in DISCOVERED state
     And dcproto a mock sandbox manager that returns a valid sandbox
     And dcproto activate_container is mocked to succeed
     When dcproto I create a sandbox for the resource with plan "plan-002"

features/steps/devcontainer_handler_protocol_methods_steps.py

@@ -152,8 +152,8 @@ def step_dcproto_container_running(context: Context) -> None:
     context.dcproto_container_state = ContainerLifecycleState.RUNNING
 
 
-@given("dcproto the container is in DETECTED state")
-def step_dcproto_container_detected(context: Context) -> None:
+@given("dcproto the container is in DISCOVERED state")
+def step_dcproto_container_discovered(context: Context) -> None:
     from cleveragents.resource.handlers._devcontainer_internals import (
         set_lifecycle_tracker,
     )