feat: preserve isolated visitor agent runtime

tests/unit/service/test_intent_agent_entrypoint.py

@@ -51,6 +51,34 @@ async def test_execute_classifies_before_handle_and_attaches_result(governance)
     assert result["intent"]["confidence"] == 0.9
 
 
+@pytest.mark.asyncio
+async def test_fixed_route_agent_skips_model_intent_classification(governance) -> None:
+    """固定路由 Agent 不能因模型意图端点不可用而阻断服务。"""
+    definition = AgentDefinition(
+        agent_type="demo", version="1", allowed_roles=("customer",),
+        allowed_portals=("api",), requires_model_intent_classification=False,
+    )
+    factory = AgentFactory(
+        governance=governance,
+        intent_classifier=IntentClassifier(StubModel()),
+        intent_endpoint_resolver=StubResolver(),
+    )
+    factory.register(definition, lambda _context: DemoAgent(definition))
+    context = RequestContext(
+        user_id="1", trace_id="fixed-route", roles=("customer",), permissions=("agent:run",)
+    )
+    request = AgentRequest(
+        agent_type="demo", message="本地路由", session_id="s",
+        idempotency_key="fixed-route-request-0001",
+    )
+
+    events = [
+        event async for event in factory.create("demo", context).execute(request, context, "run")
+    ]
+
+    assert events[-1].payload["result"]["result"]["intent"] is None
+
+
 def test_business_agent_cannot_override_intent_governance() -> None:
     with pytest.raises(TypeError, match="classify_intent"):
         class InvalidAgent(BaseAgent):