Add sideways max-loss to perpetual-options calculator.

Show premium wipeout plus flat round-trip perp fees as case C for both size and points modes.

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

manual_trading_hub/static/calculator.js

@@ -572,6 +572,35 @@
     }
   }
 
+  function renderSidewaysCase(sw) {
+    sw = sw || {};
+    return (
+      '<section class="calc-po-case">' +
+      "<h4>情景 C · 横盘(最大亏损)</h4>" +
+      '<div class="calc-summary">' +
+      "<div><span>永续盈亏</span><strong>" +
+      fmtU(sw.perp_pnl_u != null ? sw.perp_pnl_u : 0) +
+      "</strong></div>" +
+      "<div><span>权利金(全亏)</span><strong>" +
+      fmt(sw.premium_u, 2) +
+      "U</strong></div>" +
+      "<div><span>永续开平手续费</span><strong>" +
+      fmt(sw.fee_u, 2) +
+      "U</strong></div>" +
+      "<div><span>最大亏损</span><strong class=\"" +
+      pnlClass(sw.net_u) +
+      '">' +
+      fmt(sw.max_loss_u, 2) +
+      "U</strong></div>" +
+      "<div><span>组合净利</span><strong class=\"" +
+      pnlClass(sw.net_u) +
+      '">' +
+      fmtU(sw.net_u) +
+      "</strong></div>" +
+      "</div></section>"
+    );
+  }
+
   function renderPerpOptionsResult(data) {
     const box = $("calc-po-result");
     if (!box) return;
@@ -614,6 +643,11 @@
       "<div><span>永续保证金</span><strong>" +
       fmt(data.perp_margin_u, 2) +
       "U</strong></div>" +
+      "<div><span>横盘最大亏损</span><strong class=\"" +
+      pnlClass((data.case_sideways || {}).net_u) +
+      '">' +
+      fmt((data.case_sideways || {}).max_loss_u, 2) +
+      "U</strong></div>" +
       "<div><span>开仓参考</span><strong>" +
       esc(capitalHint) +
       "</strong></div>" +
@@ -663,7 +697,9 @@
       '">' +
       fmtU(b.portfolio_net_u) +
       "</strong></div>" +
-      "</div></section></div>";
+      "</div></section>" +
+      renderSidewaysCase(data.case_sideways) +
+      "</div>";
   }
 
   function renderPerpOptionsPointsResult(data) {
@@ -743,6 +779,11 @@
       "<div><span>永续保证金</span><strong>" +
       fmt(data.perp_margin_u, 2) +
       "U</strong></div>" +
+      "<div><span>横盘最大亏损</span><strong class=\"" +
+      pnlClass((data.case_sideways || {}).net_u) +
+      '">' +
+      fmt((data.case_sideways || {}).max_loss_u, 2) +
+      "U</strong></div>" +
       "<div><span>开仓参考</span><strong>" +
       esc(capitalHint) +
       "</strong></div>" +
@@ -774,6 +815,7 @@
       "</strong></div>" +
       "</div></section>" +
       caseB +
+      renderSidewaysCase(data.case_sideways) +
       "</div>";
   }