Show equivalent contract leverage on options order panel.

Display notional-over-premium leverage at current index and at the user target price for quick sizing comparison.

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

lib/options/templates/options_panel.html

@@ -46,6 +46,7 @@
                         <div><span class="k">张数</span><span id="opt-order-sheets" class="v">—</span></div>
                         <div><span class="k">ETH/BTC 数量</span><span id="opt-order-eth" class="v">—</span></div>
                         <div><span class="k">预估权利金</span><span id="opt-order-premium" class="v">—</span></div>
+                        <div><span class="k">合约杠杆</span><span id="opt-order-leverage" class="v" title="名义价值÷权利金，测算用">—</span></div>
                         <div><span class="k">到期平衡</span><span id="opt-order-expiry-be" class="v">—</span></div>
                         <div><span class="k">距平衡</span><span id="opt-order-dist-be" class="v">—</span></div>
                     </div>
@@ -54,6 +55,8 @@
                         <input type="number" id="opt-target-idx" class="opt-target-idx" step="0.1" min="0" placeholder="到期时指数价">
                         <span class="k">预计盈利</span>
                         <span id="opt-est-profit" class="v">—</span>
+                        <span class="k">目标杠杆</span>
+                        <span id="opt-est-leverage" class="v" title="目标位名义价值÷权利金">—</span>
                         <span class="muted opt-est-note">到期测算，仅供参考</span>
                     </div>
                     <div class="form-row options-order-mode-row">
@@ -133,4 +136,4 @@
         </div>
     </div>
 </div>
-<script src="/static/options_panel.js?v=8"></script>
+<script src="/static/options_panel.js?v=9"></script>