币本位开仓:张数留手续费缓冲，延长买币落账等待并修正51008文案

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

lib/options/options_coin_open_lib.py

@@ -126,7 +126,13 @@ def open_coin_option_buy_full(
             message="已买币,待开期权",
         )
         # 等余额落账
-        time.sleep(0.6)
+        time.sleep(1.5)
+        try:
+            from lib.exchange.okx_options_lib import invalidate_options_balance_cache
+
+            invalidate_options_balance_cache()
+        except Exception:
+            pass
         coin_after = fetch_trading_coin_available(ex, underlying)
         if coin_after is None:
             rb = rollback_bought_coin_to_usdt(

lib/options/options_margin_mode_lib.py

@@ -143,12 +143,14 @@ def calc_sheets_from_coin_balance(
     mult = float(ct_mult or 0.01)
     need = max(1, int(min_sz or 1))
     coin = max(0.0, float(coin_available or 0))
+    # 留一点手续费/精度缓冲,避免算满张后下单 51008
+    coin_eff = coin * 0.97
     if ask <= 0 or mult <= 0:
         return {"ok": False, "msg": "卖一价无效", "sheets": 0, "coin_premium": 0.0}
     per_sheet = ask * mult
     if per_sheet <= 0:
         return {"ok": False, "msg": "无法计算单张权利金(币)", "sheets": 0, "coin_premium": 0.0}
-    sheets = int(math.floor((coin / per_sheet) + 1e-12))
+    sheets = int(math.floor((coin_eff / per_sheet) + 1e-12))
     if sheets < need:
         return {
             "ok": False,