Fix composite margin ratio cap at 50% and add risk guide page with nav toggle.

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

static/js/dashboard.js

@@ -196,6 +196,10 @@
         }
         var marginPct = risk.margin_pct_used;
         var maxMarginPct = lim.max_margin_pct;
+        var rollMaxPct = lim.roll_max_margin_pct;
+        var isSingleMode = lim.position_mode === 'single'
+            || (maxPos != null && Number(maxPos) <= 1);
+        var compositeCapLabel = isSingleMode ? '滚仓保证金上限' : '多仓保证金上限';
 
         if (riskReasonEl) {
             var reason = st.reason || (enabled ? '可新开仓' : '风控已关闭');
@@ -227,7 +231,7 @@
             { label: '冷静剩余', value: fmtRemainSec(st.freeze_remaining_sec) },
             {
                 label: '综合保证金占比',
-                valueHtml: riskMarginPctHtml(marginPct, maxMarginPct),
+                valueHtml: riskMarginPctHtml(marginPct, rollMaxPct),
             },
             {
                 label: '单仓保证金上限',
@@ -235,8 +239,8 @@
                 valueClass: 'risk-cap-single',
             },
             {
-                label: '综合保证金上限',
-                value: lim.roll_max_margin_pct != null ? fmtNum(lim.roll_max_margin_pct) + '%' : '—',
+                label: compositeCapLabel,
+                value: rollMaxPct != null ? fmtNum(rollMaxPct) + '%' : '—',
                 valueClass: 'risk-cap-roll',
             },
             { label: '计仓模式', value: sizingDetail },