Reconstruct MLL and reconcile funds against the real starting balance

Both the MLL floor and the books-invariant fund detector assumed a $0
starting balance (correct for Express, wrong for funded/eval sizes). A
150K account (accountSize 150000) built its balance curve from $0, so
the floor came out near -$4,500 and a $145k balance never crossed it —
the account never marked dead — while reconcileFunds saw the whole
$150k as an unexplained deposit. Seed both with accountSize so the floor
is an absolute balance (150K/$4,500 drawdown → 145,500, locked at the
funded size once the EOD high climbs a drawdown above it) and the books
invariant nets out the starting balance. Skip reconcile until the
account type is known, since the start balance is unknowable before then.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

lib/topstepx-class.ts

@@ -542,13 +542,21 @@ export class TopstepXClient implements PlatformClient {
 
         const cash = this.accountCashBalances[account.id];
         if (!cash) return;
+        // The account's starting balance ($0 for Express, the funded size
+        // otherwise) is part of the balance the books must explain — without
+        // it a funded account books a phantom deposit for its whole size. Until
+        // the account type is resolved that number is unknown, so hold off
+        // rather than guess $0 and misfire on a funded account.
+        const acctType = getAccountConfig(account.id).accountType;
+        if (!acctType) return;
+        const startBal = acctType.accountSize;
         const today = currentTradeDateCT();
         const tradePnL = history
             .filter((d) => d.date !== today)
             .reduce((s, d) => s + d.pnl, 0) + cash.realizedPnL;
         const txns = this.fundTransactions[account.id] ?? [];
         const funds = txns.reduce((s, f) => s + f.amount, 0);
-        const delta = Math.round((cash.amount - tradePnL - funds) * 100) / 100;
+        const delta = Math.round((cash.amount - startBal - tradePnL - funds) * 100) / 100;
         if (Math.abs(delta) < 200) return;
 
         console.log(`[topstepx] ${account.name}: balance ${cash.amount} vs books ${Math.round((tradePnL + funds) * 100) / 100} — recording ${delta < 0 ? 'withdrawal' : 'deposit'} of ${delta}`);
@@ -588,7 +596,12 @@ export class TopstepXClient implements PlatformClient {
         // liquidates a breach and disables the account, the floor must SURVIVE
         // so the dashboards show it as blown (☠), not merely inactive. Retired
         // accounts without an assigned type fall out below via dd = 0.
-        const dd = getAccountConfig(account.id).accountType?.trailingDrawdown ?? 0;
+        const acctType = getAccountConfig(account.id).accountType;
+        const dd = acctType?.trailingDrawdown ?? 0;
+        // The account's real starting balance: $0 for Express, the funded size
+        // otherwise. Everything below is in ABSOLUTE balance terms so the floor
+        // is directly comparable to cash.amount.
+        const startBal = acctType?.accountSize ?? 0;
         const history = this.fullDailyPnL[account.id];
         const cash = this.accountCashBalances[account.id];
         if (!(dd > 0) || !history || !cash) { this.autoLiqThresholds[account.id] = 0; return; }
@@ -619,23 +632,30 @@ export class TopstepXClient implements PlatformClient {
         // any fund event detected today, neither of which is in `events`.
         const booked = dates.reduce((s, d) => s + events.get(d)!, 0);
         const todayFund = (this.fundTransactions[account.id] ?? []).find((f) => f.date === today)?.amount ?? 0;
-        const residual = Math.round((cash.amount - cash.realizedPnL - todayFund - booked) * 100) / 100;
+        // Books invariant: cash.amount = startBal + Σ(booked P&L + funds) +
+        // today's realized + today's fund. The residual is off-book fee drift.
+        const residual = Math.round((cash.amount - startBal - cash.realizedPnL - todayFund - booked) * 100) / 100;
         // Books not settled (an unabsorbed fill or an unbooked fund event) —
         // keep the previous floor rather than skewing the curve with it.
         if (Math.abs(residual) >= 200) return;
         const totalFees = dates.reduce((s, d) => s + (fees.get(d) ?? 0), 0);
 
-        let bal = 0;
-        let high = 0; // the MLL starts a full drawdown below the STARTING balance
+        let bal = startBal;
+        let high = startBal; // the MLL trails EOD balance, starting a drawdown below startBal
         for (const d of dates) {
             const drift = totalFees > 0 ? residual * ((fees.get(d) ?? 0) / totalFees) : (d === dates[0] ? residual : 0);
             bal += events.get(d)! + drift;
             if (bal > high) high = bal;
         }
 
-        const floor = high >= dd
-            ? 0.01 // locked at breakeven; one cent keeps it distinct from "no floor"
+        // Absolute floor: a drawdown below the EOD high, locked at the starting
+        // balance once the high has climbed the full drawdown above it.
+        let floor = high >= startBal + dd
+            ? startBal
             : Math.round((high - dd) * 100) / 100;
+        // 0 is the "no floor" sentinel — a real $0 floor (Express, locked at
+        // breakeven) takes a cent so it still reads as dead-eligible.
+        if (floor === 0) floor = 0.01;
         this.autoLiqThresholds[account.id] = floor;
     }