Add max_position_size to account configs

- DB migration: ALTER TABLE account_configs ADD COLUMN max_position_size INTEGER NOT NULL DEFAULT 0
- Added max_position_size to AccountConfigRow, createAccountConfig, updateAccountConfig in lib/db.ts
- Added maxPositionSize to AccountConfig type in types.ts (0 = no limit)
- GET /api/firms/[id] now returns maxPositionSize per account
- POST /api/firms/[id]/accounts and PUT /api/account-configs/[id] accept maxPositionSize
- Firm settings page: new Max Contracts column (blank = no limit)
- auto-trade: contracts capped at maxPositionSize when > 0

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/auto-trade.ts

@@ -41,6 +41,7 @@ function mapFirmConfig(firm: FirmWithAccounts): FirmConfig {
             minTradingDays: a.min_trading_days,
             accountSize: a.account_size,
             maxLoss: a.max_loss,
+            maxPositionSize: a.max_position_size,
         })),
     };
 }
@@ -124,7 +125,8 @@ export async function runTrade(action: 'Buy' | 'Sell', symbol: string) {
         const totalProfit = dailyPnL.reduce((sum, d) => sum + d.pnl, 0);
         const target = computeDailyTarget(cfg.profitTarget, cfg.consistency, totalProfit, dailyPnL);
 
-        const contracts = Math.max(1, Math.ceil(target.amount / 1000));
+        const rawContracts = Math.max(1, Math.ceil(target.amount / 1000));
+        const contracts = cfg.maxPositionSize > 0 ? Math.min(rawContracts, cfg.maxPositionSize) : rawContracts;
         const fill = await client.sendOrder(acc.id, contract.name, contracts, action, 'Market');
 
         // Wait briefly for the cash balance WebSocket update to reflect entry commission

lib/db.ts

@@ -43,6 +43,13 @@ try {
     // Column already exists
 }
 
+// Migration: add max_position_size column (0 = no limit)
+try {
+    db.exec('ALTER TABLE account_configs ADD COLUMN max_position_size INTEGER NOT NULL DEFAULT 0');
+} catch {
+    // Column already exists
+}
+
 // Seed default firms if empty
 const firmCount = (db.prepare('SELECT COUNT(*) as count FROM firms').get() as { count: number }).count;
 if (firmCount === 0) {
@@ -77,6 +84,7 @@ export interface AccountConfigRow {
     min_trading_days: number;
     account_size: number;
     max_loss: number;
+    max_position_size: number;
 }
 
 export interface FirmRow {
@@ -129,11 +137,12 @@ export function createAccountConfig(firmId: number, data: {
     minTradingDays: number;
     accountSize: number;
     maxLoss: number;
+    maxPositionSize: number;
 }): AccountConfigRow {
     const stmt = db.prepare(
-        'INSERT INTO account_configs (firm_id, prefix, profit_target, consistency, min_day_pnl, min_trading_days, account_size, max_loss) VALUES (?, ?, ?, ?, ?, ?, ?, ?)'
+        'INSERT INTO account_configs (firm_id, prefix, profit_target, consistency, min_day_pnl, min_trading_days, account_size, max_loss, max_position_size) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)'
     );
-    const result = stmt.run(firmId, data.prefix, data.profitTarget, data.consistency, data.minDayPnL, data.minTradingDays, data.accountSize, data.maxLoss);
+    const result = stmt.run(firmId, data.prefix, data.profitTarget, data.consistency, data.minDayPnL, data.minTradingDays, data.accountSize, data.maxLoss, data.maxPositionSize);
     return db.prepare('SELECT * FROM account_configs WHERE id = ?').get(result.lastInsertRowid) as AccountConfigRow;
 }
 
@@ -150,12 +159,13 @@ export function updateAccountConfig(id: number, data: {
     minTradingDays: number;
     accountSize: number;
     maxLoss: number;
+    maxPositionSize: number;
 }): boolean {
     const result = db.prepare(`
         UPDATE account_configs
-        SET prefix = ?, profit_target = ?, consistency = ?, min_day_pnl = ?, min_trading_days = ?, account_size = ?, max_loss = ?
+        SET prefix = ?, profit_target = ?, consistency = ?, min_day_pnl = ?, min_trading_days = ?, account_size = ?, max_loss = ?, max_position_size = ?
         WHERE id = ?
-    `).run(data.prefix, data.profitTarget, data.consistency, data.minDayPnL, data.minTradingDays, data.accountSize, data.maxLoss, id);
+    `).run(data.prefix, data.profitTarget, data.consistency, data.minDayPnL, data.minTradingDays, data.accountSize, data.maxLoss, data.maxPositionSize, id);
     return result.changes > 0;
 }