Fix historical chart blank — ISO time strings rejected by LightweightCharts

The historical runner stores equity curve times as ISO strings like
"2026-07-05T07:00:00" but LightweightCharts only accepts Unix timestamps.
Chart was loading 721 data points but rendering blank because time values
were silently rejected.

Changes:
- renderBTDetail: convert string times to Unix timestamps before setData()
- openDetail: same conversion for live/paper detail charts
- pushEquity: same conversion for main area equity charts

All chart codepaths now handle both string ISO and numeric timestamps.

dashboard/static/index.html

@@ -322,7 +322,7 @@ function renderBTDetail(full){
   // Equity chart
   if(!detChart)initDetChart();
   var pts=[],curve=full.equity_curve||[];
-  for(var i=0;i<curve.length;i++){if(curve[i]&&curve[i].t)pts.push({time:curve[i].t,value:curve[i].v})}
+  for(var i=0;i<curve.length;i++){if(curve[i]&&curve[i].t)var ct=curve[i].t;if(typeof ct==="string")ct=Math.floor(new Date(ct).getTime()/1000);pts.push({time:ct,value:curve[i].v})}
   if(pts.length>0){detSer.setData(pts);detChart.timeScale().fitContent();setTimeout(function(){detChart.timeScale().fitContent()},200)}
   // Trades table (show pnl_net or pnl_gross based on toggle)
   var trows='',tlist=full.trades||[];
@@ -391,7 +391,7 @@ function openDetail(name,tab){
   if(!detChart)initDetChart();
   var eqData=Array.isArray(equity)?equity:(equity[name]||[]);
   if(eqData.length>0){
-    var pts=[];for(var i=0;i<eqData.length;i++){if(eqData[i]&&eqData[i].t)pts.push({time:eqData[i].t,value:eqData[i].v})}
+    var pts=[];for(var i=0;i<eqData.length;i++){if(eqData[i]&&eqData[i].t){var edt=eqData[i].t;if(typeof edt==='string')edt=Math.floor(new Date(edt).getTime()/1000);pts.push({time:edt,value:eqData[i].v})}}
     detSer.setData(pts);detChart.timeScale().fitContent();
   }