关键位监控币种改为仅 BTC/USDT、ETH/USDT 下拉，对齐期权标的。

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

app.py

@@ -6547,6 +6547,9 @@ def add_key():
     if not symbol:
         flash("symbol 不能为空")
         return redirect("/key_monitor")
+    if symbol not in ("BTC/USDT", "ETH/USDT"):
+        flash("关键位仅支持 BTC/USDT、ETH/USDT(对应期权标的)")
+        return redirect("/key_monitor")
     ok_sym, sym_msg = check_symbol_policy(
         TRADE_POLICY, symbol, normalize_symbol_input
     )

lib/instance/templates/key_monitor_panel.html

@@ -140,8 +140,10 @@
         {% endif %}
     </div>
     <form id="key-form" action="/add_key" method="post" class="form-row">
-        {% from 'trade_policy_fields.html' import trade_policy_symbol with context %}
-        {{ trade_policy_symbol('symbol', 'key-symbol') }}
+        <select name="symbol" id="key-symbol" required class="trade-policy-symbol-select" title="仅 BTC/ETH，与期权标的一致">
+            <option value="ETH/USDT" selected>ETH/USDT</option>
+            <option value="BTC/USDT">BTC/USDT</option>
+        </select>
         <select name="type" id="key-type-select" required>
             <option value="关键支撑阻力" selected>关键支撑阻力</option>
         </select>