fix(trend): use mark price for DCA trigger on gate_bot

Poll trend plans with mark price (same as UI) instead of ticker last, add get_symbol_mark_price to gate_bot, tolerate position API blips, and log DCA order failures.

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

crypto_monitor_gate_bot/app.py

@@ -4370,6 +4370,24 @@ def get_price(symbol):
     except:
         return None
 
+
+def get_symbol_mark_price(symbol):
+    """趋势补仓/标记价展示：优先 ticker.mark，与页面浮盈亏口径一致。"""
+    ex_sym = normalize_exchange_symbol(symbol)
+    try:
+        ensure_markets_loaded()
+        ticker = exchange.fetch_ticker(ex_sym)
+        m = _coerce_float(ticker.get("mark"), ticker.get("last"))
+        if m is None:
+            info = ticker.get("info") or {}
+            m = _coerce_float(info.get("mark_price"), info.get("last"))
+        if m is not None and m > 0:
+            return float(m)
+    except Exception:
+        pass
+    p = get_price(symbol)
+    return float(p) if p is not None else None
+
 # 获取5分钟K线收盘价
 def get_5m_close(symbol):
     try: