Fix seven type errors that broke next build

`npm run build` failed on a clean checkout, so nothing on master could be
built for production. `npm run dev` does not hard-fail on type errors, which
is why it went unnoticed.

- state route returned client.perContractFees, which has never existed on
  TradovateClient on any branch; nothing consumed it
- mapFirmConfig omitted bannedSymbols. Type gap only: the trade path calls
  isSymbolBanned() against the DB directly, so bans were always enforced
- initClient's sync callback was sync where the constructor wants
  () => Promise<void>
- accessInfo and ws are assigned during async connect/auth, never in the
  constructor, so they take definite-assignment assertions
- the socket payload's inline entityType union had drifted five members
  behind the indirect-callback union above it, making the 'position' and
  'cashBalance' branches unreachable to the compiler. Both now share a
  TradovateEntityType alias. Type-only: those handlers ran fine at runtime

Behaviour is unchanged throughout.

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

lib/auto-trade.ts

@@ -7,7 +7,7 @@
  * signal but have since exited and are now eligible.
  */
 
-import { getFirms, isSymbolBanned, getInstruments } from './db';
+import { getFirms, isSymbolBanned, getInstruments, getBannedSymbols } from './db';
 import { getClients } from './clients';
 import { computeDailyTarget, resolveEffectiveConfig, POINT_VALUES } from './trading-logic';
 import { getSetting } from './db';
@@ -33,6 +33,7 @@ function mapFirmConfig(firm: FirmWithAccounts): FirmConfig {
         firm: firm.name,
         username: firm.username,
         password: firm.password,
+        bannedSymbols: getBannedSymbols(firm.id),
         accounts: firm.accounts.map((a) => ({
             prefix: a.prefix,
             profitTarget: a.profit_target,