fix(agent): polish interrupt-resume flow for merge readiness

backend/tests/unit/v1/agent/test_tool_dispatcher.py

@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import pytest
+
 from v1.agent.tool_dispatcher import (
     BackendExecutionResult,
     InterruptResult,
@@ -46,9 +48,18 @@ class TestToolDispatcher:
     def test_dispatcher_class_can_dispatch(self):
         dispatcher = ToolDispatcher()
         tool = {
-            "name": "ui.show_dialog",
+            "name": "ui.navigate_to",
             "execution_target": "frontend",
             "args": {"message": "Hello"},
         }
         result = dispatcher.dispatch(tool)
         assert isinstance(result, InterruptResult)
+
+    def test_unknown_frontend_tool_is_rejected(self):
+        tool = {
+            "name": "ui.unknown_action",
+            "execution_target": "frontend",
+            "args": {},
+        }
+        with pytest.raises(ValueError, match="not in allowlist"):
+            dispatch_tool_call(tool)