DXtrade: count closed-trade P&L, week-long volatility, broker leverage caps, swap in the take-profit

- Transfers: a close books its SETTLEMENT and COMMISSION under one
  transaction code, and keying by the code alone let the commission
  overwrite the P&L. Keys now carry the type, so the day-start balance,
  daily-loss room, realized P&L, daily history and books check all see
  closed-trade profit and loss.
- Volatility from a week of hourly closes (was 48 h), still measured once
  per trade date, so one quiet weekend can't triple a hold estimate.
- Each symbol's margin rate from the account's instrument details caps
  the position at available funds / rate (Tradeify: 5:1 crypto, 2:1
  stocks); the account type's max notional stays as an optional ceiling.
- Firms with overnight financing add the swap a winning leg is expected
  to pay (the winners' mean hold, (A²+2AB)/3σ²) to its take-profit, and
  the sizing and hold estimate count it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

app/page.tsx

@@ -393,8 +393,11 @@ function AccountRow({ account, firm, hideDead, privacy, onAssigned }: {
                             {account.holdEstimate && (
                                 <span
                                     className="text-slate-500"
-                                    title={`Next leg on ${account.holdEstimate.symbol}: $${Math.round(account.holdEstimate.notional).toLocaleString()} notional at today's measured volatility of ${(account.holdEstimate.volatilityPerDay * 100).toFixed(2)}%/day`
-                                        + (account.holdEstimate.winProbability !== null ? `, wins ~${Math.round(account.holdEstimate.winProbability * 100)}% of the time` : '')}
+                                    title={`Next leg on ${account.holdEstimate.symbol}: $${Math.round(account.holdEstimate.notional).toLocaleString()} notional`
+                                        + (account.holdEstimate.leverage !== null ? ` (${account.holdEstimate.leverage}:1 max)` : '')
+                                        + ` at a measured volatility of ${(account.holdEstimate.volatilityPerDay * 100).toFixed(2)}%/day over the past week`
+                                        + (account.holdEstimate.winProbability !== null ? `, wins ~${Math.round(account.holdEstimate.winProbability * 100)}% of the time` : '')
+                                        + (account.holdEstimate.swapReserve > 0 ? `; its take-profit carries ~$${fmt(account.holdEstimate.swapReserve)} of expected swap` : '')}
                                 >
                                     {' · hold ~'}{account.holdEstimate.hours < 48 ? `${Math.round(account.holdEstimate.hours)}h` : `${(account.holdEstimate.hours / 24).toFixed(1)}d`}
                                 </span>