Estimate missing option ask from mark or intrinsic on chain list.

Deep ITM contracts often have no ask on the book; show mark-based estimates with a tilde and restore breakeven calculations.

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

lib/options/templates/options_panel.html

@@ -7,7 +7,7 @@
     <div class="options-dual-grid">
         <div class="card options-order-card">
             <h2>期权下单</h2>
-            <p class="muted options-hint">报价单位为每 1 ETH/BTC；1 张 = 0.01。卖一/买一列为 <strong>价格/张数</strong>。链展示近 <span id="opt-chain-dte">14</span> 日到期，标注实值/虚值；<strong>到期平衡</strong>按卖一预估（无卖一按标记价）。资金划转与 USDT/USDC 兑换见「系统设置 → 期权设置」。</p>
+            <p class="muted options-hint">报价单位为每 1 ETH/BTC；1 张 = 0.01。卖一/买一列为 <strong>价格/张数</strong>；卖一无挂单时以标记价估算并标 <strong>~</strong>。链展示近 <span id="opt-chain-dte">14</span> 日到期，标注实值/虚值；<strong>到期平衡</strong>按卖一预估（无卖一按标记价）。资金划转与 USDT/USDC 兑换见「系统设置 → 期权设置」。</p>
             <div class="form-row options-chain-toolbar">
                 <button type="button" class="btn-secondary opt-uly-btn active" data-uly="ETH">ETH</button>
                 <button type="button" class="btn-secondary opt-uly-btn" data-uly="BTC">BTC</button>
@@ -136,4 +136,4 @@
         </div>
     </div>
 </div>
-<script src="/static/options_panel.js?v=9"></script>
+<script src="/static/options_panel.js?v=10"></script>