fix: fall back to latest SGE trading price

tests/test_today_environment.py

@@ -56,6 +56,61 @@ def test_parse_sge_rejects_changed_structure_or_invalid_quote(html):
         environment.parse_sge_au9999(html)
 
 
+@pytest.mark.asyncio
+async def test_fetch_gold_falls_back_to_latest_trading_day_when_delayed_quote_is_zero():
+    delayed_html = SGE_HTML.replace("2026年09月16日", "2026年09月20日").replace(
+        "935.99", "0.0"
+    )
+    history_html = """
+    <table>
+    <tr><th>序号</th><th>日期</th><th>合约</th><th>开盘价</th><th>收盘价</th></tr>
+    <tr><td>1</td><td>2026-09-17</td><td>Au99.99</td><td>937.50</td><td>934.81</td></tr>
+    <tr><td>2</td><td>2026-09-18</td><td>Au99.99</td><td>937.00</td><td>947.09</td></tr>
+    <tr><td>3</td><td>2026-09-16</td><td>Au99.99</td><td>-</td><td>-</td></tr>
+    </table>
+    """
+    seen = []
+
+    async def request(url, **_kwargs):
+        seen.append(url)
+        return delayed_html if url == environment.GOLD_URL else history_html
+
+    result = await environment.fetch_gold(request)
+
+    assert seen == [
+        environment.GOLD_URL,
+        environment.GOLD_HISTORY_URL.format(start_date="2026-08-20", end_date="2026-09-20"),
+    ]
+    assert result["latest_price"] == Decimal("947.09")
+    assert result["market_date"] == "2026-09-18"
+
+
+@pytest.mark.asyncio
+async def test_gold_source_has_time_for_two_sequential_upstream_requests(monkeypatch):
+    environment.clear_cache()
+    monkeypatch.setattr(environment, "SOURCE_TIMEOUT_SECONDS", 0.01)
+    monkeypatch.setattr(environment, "GOLD_SOURCE_TIMEOUT_SECONDS", 0.05, raising=False)
+    monkeypatch.setattr(environment, "TOTAL_TIMEOUT_SECONDS", 0.06)
+
+    async def weather():
+        return {"temperature_c": 25, "source": "Open-Meteo"}
+
+    async def gold():
+        await asyncio.sleep(0.03)
+        return {
+            "contract": "Au99.99",
+            "latest_price": Decimal("947.09"),
+            "market_date": "2026-09-18",
+            "delayed": True,
+            "source": "上海黄金交易所",
+        }
+
+    result = await environment.get_environment(weather_fetcher=weather, gold_fetcher=gold)
+
+    assert result["gold"]["latest_price"] == "947.09"
+    assert result["errors"] == {}
+
+
 @pytest.mark.asyncio
 async def test_fetch_weather_uses_fixed_haishu_location_and_current_conditions():
     seen = {}