[Bugfix] Validate sleep stage_ids before blocking admission (#8501)

Signed-off-by: Yufeng He <40085740+he-yufeng@users.noreply.github.com>

tests/entrypoints/openai_api/test_omni_sleep_wakeup.py

@@ -125,9 +125,10 @@ def test_sleep_client_error_does_not_mark_stages(sleep_capable_engine, mocker):
     app = _make_app(sleep_capable_engine)
     client = TestClient(app)
 
-    with pytest.raises(ValueError, match="unknown stage id 9"):
-        client.post("/v1/omni/sleep", json={"stage_ids": [9], "level": 1})
+    response = client.post("/v1/omni/sleep", json={"stage_ids": [9], "level": 1})
 
+    assert response.status_code == 400
+    assert "unknown stage id 9" in response.json()["detail"]
     assert app.state.sleeping_stages == set()
 
 
@@ -213,6 +214,19 @@ def test_wakeup_failure_returns_error_and_keeps_sleeping_set(sleep_capable_engin
     assert app.state.sleeping_stages == {0}
 
 
+def test_wakeup_client_error_returns_400_and_keeps_sleeping_set(sleep_capable_engine, mocker):
+    sleep_capable_engine.wake_up = mocker.AsyncMock(side_effect=ValueError("unknown stage id 9"))
+    app = _make_app(sleep_capable_engine)
+    app.state.sleeping_stages = {0, 9}
+    client = TestClient(app)
+
+    response = client.post("/v1/omni/wakeup", json={"stage_ids": [9]})
+
+    assert response.status_code == 400
+    assert "unknown stage id 9" in response.json()["detail"]
+    assert app.state.sleeping_stages == {0, 9}
+
+
 def test_wakeup_engine_not_support(sleep_incapable_engine):
     app = _make_app(sleep_incapable_engine)
     app.state.sleeping_stages = {0}