K线后台自动刷新并通过SSE推送到前端，移除轮询

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

kline_chart.py

@@ -215,7 +215,12 @@ def bars_to_api(bars: list) -> list[dict]:
     return result
 
 
-def fetch_market_klines(symbol: str, period: str, db_path: Optional[str] = None) -> dict:
+def fetch_market_klines(
+    symbol: str,
+    period: str,
+    db_path: Optional[str] = None,
+    force_remote: bool = False,
+) -> dict:
     chart_sym = ths_to_sina_chart_symbol(symbol)
     p = (period or "15m").lower()
     if p == "timeshare":
@@ -227,7 +232,7 @@ def fetch_market_klines(symbol: str, period: str, db_path: Optional[str] = None)
     source = "remote"
     cached_at = None
 
-    if db_path and chart_sym:
+    if db_path and chart_sym and not force_remote:
         try:
             conn = sqlite3.connect(db_path)
             cached = get_cached_entry(conn, chart_sym, p)
@@ -239,7 +244,7 @@ def fetch_market_klines(symbol: str, period: str, db_path: Optional[str] = None)
         except Exception as exc:
             logger.warning("kline cache read failed %s %s: %s", chart_sym, p, exc)
 
-    if not bars:
+    if force_remote or not bars:
         remote_bars = fetch_sina_klines(symbol, p)
         if remote_bars:
             bars = remote_bars
@@ -257,7 +262,7 @@ def fetch_market_klines(symbol: str, period: str, db_path: Optional[str] = None)
                     cached_at = meta[0] if meta else None
                 except Exception as exc:
                     logger.warning("kline cache write failed %s %s: %s", chart_sym, p, exc)
-        elif db_path and chart_sym:
+        elif not bars and db_path and chart_sym:
             try:
                 conn = sqlite3.connect(db_path)
                 cached = get_cached_entry(conn, chart_sym, p)