feat(planner): persist reusable action semantics

tests/test_world_model.py

@@ -61,7 +61,9 @@ def test_observe_leaves_current_page_unchanged_without_semantic_scene() -> None:
     assert model.state.current_page == "Chat"
 
 
-def test_observe_updates_current_app_for_successful_launch_and_clear_for_terminate() -> None:
+def test_observe_updates_current_app_for_successful_launch_and_clear_for_terminate() -> (
+    None
+):
     model = WorldModel(config=WorldConfig(history_size=2))
     launch = PlannedStep(
         action="launch_app",
@@ -188,3 +190,22 @@ def test_observe_appends_semantic_or_raw_scene_history_with_eviction() -> None:
     assert [event.action for event in model.state.history] == ["second", "third"]
     assert model.state.history[0].scene_summary.to_dict() == _scene().to_dict()
     assert model.state.history.maxlen == 2
+
+
+def test_observe_records_executed_action_arguments_and_metadata() -> None:
+    model = WorldModel(config=WorldConfig(history_size=2))
+    step = PlannedStep(
+        action="tap",
+        description="Open settings.",
+        args={"x": 12, "y": 34},
+        purpose="Open settings.",
+        expected_outcome="The settings page is visible.",
+    )
+
+    model.observe(_scene(), _semantic_scene("Settings"), step, _result(step))
+
+    event = model.state.history[0]
+    assert event.action == "tap"
+    assert event.arguments == {"x": 12, "y": 34}
+    assert event.purpose == "Open settings."
+    assert event.expected_outcome == "The settings page is visible."