feat(data): 15min双源集成(data_source路由 + baostock格式适配)

- _resolve_dir_key: 15min支持raw/qfq双源(移除raw15min抛错)
- _check_adjust_cfg: 按interval查dir(minute_15_raw_dir/qfq_dir)
- read_parquet_15min: datetime列优先(baostock时分,旧date兼容)
- config: 加 minute_15_qfq_dir/minute_15_raw_dir
- test: 更新raw15min路由断言(6 passed)

实测容器: 600000 15min qfq 336bars close6.1977 / raw 336bars close6.6200,
datetime时分正确(09:45:00). 15min双源分期项落地.

tests/trader/test_data_source.py

@@ -65,15 +65,20 @@ def test_iter_bars_raw_missing_dir_raises(monkeypatch):
                        adjust="raw", cfg=_cfg({})))
 
 
-def test_iter_bars_raw_15min_unsupported(monkeypatch):
-    """raw 仅日线；15min+raw 报错（raw 15min 待分期项）。"""
+def test_iter_bars_raw_15min_routes_dedicated_dir(monkeypatch):
+    """raw 15min 路由 minute_15_raw_dir（baostock 双源，分期项已落地）。"""
+    seen = []
     monkeypatch.setattr(
         "sanguo_trader.data_source._read_fn",
-        lambda iv: lambda s, st, e, c, dir_key: [],
+        lambda iv: lambda s, st, e, c, dir_key: seen.append(dir_key) or [],
     )
-    with pytest.raises(ValueError, match="日线"):
+    list(iter_bars(["600000"], "2024-01-01", "2024-01-31", "15m",
+                   adjust="raw", cfg=_cfg({"minute_15_raw_dir": "/x"})))
+    assert seen == ["minute_15_raw_dir"]
+    # 缺 minute_15_raw_dir 配置 → 明确报错（不 fallback，防混源）
+    with pytest.raises(ValueError, match="minute_15_raw_dir"):
         list(iter_bars(["600000"], "2024-01-01", "2024-01-31", "15m",
-                       adjust="raw", cfg=_cfg({"raw_dir": "/x"})))
+                       adjust="raw", cfg=_cfg({})))
 
 
 def test_unsupported_interval_rejected():