Add day-plan double-count diagnostics

The daily target sometimes inflates to base + consistency×todayPnL (e.g.
1200 + 0.4×1218.48 = 1687.39), which happens when a session's cached
daily-P&L row is dated something other than the current tradeDate: it
then lands in BOTH the prior-day list and realizedPnL, so day-start
equity reads too low while the prior-day sum stays high.

Detect it with a book-balance invariant that is coincidence-proof (it
does not care whether prior and today P&L happen to be equal): the
reconstructed day-start equity (equityProfit − realizedPnL) must equal
priorProfit + sum(prior days). The state route now logs the full account
state whenever those disagree by more than $50, and GET /api/debug
reports the same per-account breakdown on demand (?account=<substring>)
so the exact inputs can be captured the moment a number looks wrong.

Read-only; no behavior change. Remove once the trigger is fixed.

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

app/api/debug/route.ts

@@ -1,12 +1,59 @@
 import { NextResponse } from 'next/server';
 import { getClients, resetClients } from '@/lib/clients';
 import { getTradableFirms } from '@/lib/firm-catalog';
+import { getAccountConfig } from '@/lib/account-type-resolver';
+import { combineCmeSessions, computeDayPlan, resolveEffectiveConfig, currentTradeDateCT } from '@/lib/trading-logic';
 import axios from 'axios';
 
-export async function GET() {
+/**
+ * Per-account snapshot of everything computeDayPlan sees, plus the book-balance
+ * check the state route warns on: day-start equity (equityProfit − realizedPnL)
+ * must equal priorProfit + sum(prior days). A large `drift` means a session is
+ * counted in both the prior-day list and realizedPnL — the daily-target inflation
+ * bug. Filter with ?account=<substring> (case-insensitive). Read-only.
+ */
+function dayPlanDiag(client: any, acc: { id: number; name: string }, tradeDate: string) {
+    const cfg = getAccountConfig(acc.id).accountType;
+    const cash = client.accountCashBalances[acc.id] ?? { amount: 0, realizedPnL: 0 };
+    if (!cfg) return { tradeDate, note: 'no account type assigned', cash, rawDailyPnL: client.dailyPnL[acc.id] ?? [] };
+
+    const priorProfit = client.priorProfit?.[acc.id] ?? 0;
+    const allFundTxns = client.fundTransactions?.[acc.id] ?? [];
+    const combined = combineCmeSessions(cfg.combineCmeHolidays === true, client.dailyPnL[acc.id] ?? [], tradeDate, cash.realizedPnL);
+    const effective = resolveEffectiveConfig(cfg.profitTarget, cfg.consistency, cfg.minTradingDays, cfg.targetSameEquity, cfg.withdrawalStages, priorProfit, allFundTxns);
+    const equityProfit = cash.amount - cfg.accountSize;
+    const plan = computeDayPlan(acc.id, combined.tradeDate, effective.profitTarget, effective.consistency, combined.dailyPnL, cfg.minDayPnL, effective.minTradingDays, equityProfit, combined.realizedPnL, cfg.splitEnabled);
+
+    const priorDaysSum = combined.dailyPnL.filter((d) => d.date !== combined.tradeDate).reduce((s, d) => s + d.pnl, 0);
+    const dayStartEquity = Math.round((equityProfit - combined.realizedPnL) * 100) / 100;
+    const expectedDayStart = Math.round((priorProfit + priorDaysSum) * 100) / 100;
+
+    return {
+        tradeDate: combined.tradeDate,
+        drift: Math.round((dayStartEquity - expectedDayStart) * 100) / 100,
+        dayStartEquity,
+        expectedDayStart,
+        equityProfit,
+        realizedPnL: combined.realizedPnL,
+        priorProfit,
+        priorDaysSum: Math.round(priorDaysSum * 100) / 100,
+        dayTarget: plan?.dayTarget ?? null,
+        remainingToday: plan?.remainingToday ?? null,
+        path: plan?.path ?? null,
+        consistency: effective.consistency,
+        hasTodayRow: combined.dailyPnL.some((d) => d.date === combined.tradeDate),
+        combineCmeHolidays: cfg.combineCmeHolidays === true,
+        combinedDailyPnL: combined.dailyPnL,
+        rawDailyPnL: client.dailyPnL[acc.id] ?? [],
+    };
+}
+
+export async function GET(req: Request) {
     try {
         const clients = getClients();
         const firms = getTradableFirms();
+        const tradeDate = currentTradeDateCT();
+        const nameFilter = (new URL(req.url).searchParams.get('account') ?? '').toLowerCase();
 
         const debug = firms.map((firm) => {
             const client = clients.get(firm.id);
@@ -20,13 +67,16 @@ export async function GET() {
                 fetchDaysComplete: (client as any).fetchDaysComplete ?? 'n/a (old instance)',
                 lastFetchErrors: (client as any).lastFetchErrors ?? {},
                 lastFetchRaw: (client as any).lastFetchRaw ?? {},
-                accounts: client.accountList.map((acc) => ({
+                accounts: client.accountList
+                    .filter((acc) => !nameFilter || acc.name.toLowerCase().includes(nameFilter))
+                    .map((acc) => ({
                     id: acc.id,
                     name: acc.name,
                     cash: client.accountCashBalances[acc.id] ?? null,
                     daysTraded: client.daysTraded[acc.id] ?? '(not set)',
                     dailyPnLEntries: (client.dailyPnL[acc.id] ?? []).length,
                     dailyPnL: client.dailyPnL[acc.id] ?? [],
+                    dayPlan: dayPlanDiag(client, acc, tradeDate),
                 })),
                 recentEntityEvents: client.recentEntityEvents.slice(-10).map((e) => ({
                     ts: new Date(e.ts).toISOString(),