行情K线：分类主力选择、图表指标与布局稳定

Co-authored-by: Cursor <cursoragent@cursor.com>

kline_chart.py

@@ -274,13 +274,19 @@ def fetch_market_klines(
             except Exception as exc:
                 logger.warning("kline cache fallback failed %s %s: %s", chart_sym, p, exc)
 
+    api_bars = bars_to_api(bars)
+    prev_close = None
+    if len(api_bars) >= 2:
+        prev_close = api_bars[-2]["close"]
+
     return {
         "symbol": symbol,
         "chart_symbol": chart_sym,
         "period": p,
         "chart_type": chart_type,
         "count": len(bars),
-        "bars": bars_to_api(bars),
+        "bars": api_bars,
+        "prev_close": prev_close,
         "source": source,
         "cached_at": cached_at,
     }