Trades: record every firm's trades, not just Vest's, and list them on each

TopstepX and Tradovate report fills, so a trade is built from them, flat
to flat (lib/fill-trades.ts), off the window each sync already reads:
TopstepX's two days of Trade/search, Tradovate's sync snapshot. Neither
says who placed an order, so every order the bot places is noted in
own_orders, and a trade is the bot's when its opening fill's order is
one; its stop or take-profit closing it reads as such. A contract is
written only when the position before its window comes out the same
two passes running, so a fill landing between the position and history
reads can't build the wrong trades.

DXtrade reports positions: its record groups the last two days' filled
orders by position code, with each close's SETTLEMENT and COMMISSION.
The bot's own orders carry af- codes, so nothing is kept locally. Only
accounts with something going on are read, at most every 5 minutes.

The Trades button shows on every firm with a login, and the account
page lists any account's trades.

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

app/page.tsx

@@ -652,7 +652,7 @@ function FirmRows({ state, firm, hideDead, privacy, sortKey, sortDir, tradeSymbo
                 )}
                 <td className="px-4 py-3.5">
                     <div className="flex items-center justify-end gap-1">
-                        {firm.platform === 'vest' && hasCredentials && (
+                        {hasCredentials && (
                             <button
                                 onClick={(e) => { e.stopPropagation(); setShowTrades((v) => !v); }}
                                 className={`px-2 py-0.5 text-xs font-semibold rounded-md transition-colors ${showTrades ? 'bg-violet-100 text-violet-700' : 'text-slate-500 hover:bg-slate-200'}`}