feat(web): trade detail modal with prices, fees, timestamps

- Click any trade row in history table to open detail modal
- Modal shows 6 sections: 概览, 时间, 价差, 手续费, 多仓, 空仓
- Entries and exits displayed with 6 decimal precision
- Fee entry/exit and total fee displayed
- Open/close timestamps with full date-time format
- Duration, scale count, total amount, exit reason
- Orders sub-table if available
- Escape key and overlay click to close

main.go

@@ -183,7 +183,7 @@ func main() {
 			// Profile: warn if any step is slow
 			tickDur := t3.Sub(t0)
 			tickMs := tickDur.Milliseconds()
-			if tickMs > 100 || t1.Sub(t0) > 50 || t2.Sub(t1) > 50 || t3.Sub(t2) > 50 {
+			if tickMs > 100 || t1.Sub(t0) > 50*time.Millisecond || t2.Sub(t1) > 50*time.Millisecond || t3.Sub(t2) > 50*time.Millisecond {
 				log.Printf("[Profile] tick=%dms trader=%dms scan=%dms entry=%dms",
 					tickMs, t1.Sub(t0).Milliseconds(), t2.Sub(t1).Milliseconds(), t3.Sub(t2).Milliseconds())
 			}