Legs: cheapest symbol that reaches the target hold, last stands, a reserve that grows with size

- A batch sizes its leg on every mapped candidate, each at the leverage
  the broker states for it, and trades the cheapest (spread, commissions,
  expected swap) that reaches the target hold — else the quickest. The
  dashboard ranks the same way from a half-hourly candidate survey.
- Last stand: when a daily-loss stop-out would leave the account within
  15% of that loss above its max-drawdown floor (the account type's static
  max loss, or the broker's liquidation floor), the leg carries no
  daily-loss stop and is sized against the firm's own breach.
- The daily-loss reserve is 10% of the limit or 0.1% of the position,
  whichever is more, since a stop's slippage grows with the position.
- The account type's max notional is gone: the broker's margin rates cap
  each symbol. planLegSize holds the one sizing rule fireLeg, the pick and
  the dashboard share.

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

lib/firm-catalog.ts

@@ -233,7 +233,6 @@ function validatePayload(raw: unknown): FirmCatalogPayload {
                 minDayStop: type.minDayStop === true,
                 // Lenient: no hard daily limit, no notional cap.
                 dailyLossLimit: nonNegative(type.dailyLossLimit),
-                maxNotional: nonNegative(type.maxNotional),
                 // The firm's calendar, stamped on every type so the cfg-based
                 // paths (projections, completion, the dashboard) all see it.
                 tradesEveryDay,