Add per-account-type splitEnabled flag from the catalog

When the master marks an account type splitEnabled=false, big days trade
as one unsplit leg (the legacy one-and-done behavior); min-day bumps are
unaffected. Missing field — older master or pre-toggle cached catalog —
defaults to enabled.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

lib/trading-logic.ts

@@ -242,7 +242,8 @@ export interface DayPlan {
     /** dayTarget minus what's already realized today; what's left to trade. */
     remainingToday: number;
     path: 'first_day' | 'normal_day' | 'reduced_day';
-    /** False for strict-consistency accounts past their first trade ever — single unsplit trade. */
+    /** False when the account type disables splitting, or for strict-consistency
+     *  accounts past their first trade ever — single unsplit trade. */
     splitAllowed: boolean;
 }
 
@@ -264,7 +265,8 @@ export function computeDayPlan(
     minDayPnL: number,
     minTradingDays: number,
     equityProfit: number | null | undefined,
-    realizedPnL: number
+    realizedPnL: number,
+    splitEnabled: boolean = true
 ): DayPlan | null {
     if (typeof equityProfit !== 'number' || !Number.isFinite(equityProfit)) return null;
 
@@ -277,7 +279,7 @@ export function computeDayPlan(
     if (!target) return null;
 
     const qualifyingDays = minDayPnL === 0 ? priorDays : priorDays.filter((d) => d.pnl >= minDayPnL);
-    const splitAllowed = consistency === 0 || consistency >= 1 || qualifyingDays.length === 0;
+    const splitAllowed = splitEnabled && (consistency === 0 || consistency >= 1 || qualifyingDays.length === 0);
 
     return {
         dayTarget: target.amount,