Broker sessions rest while nothing needs them

A firm's client used to stay logged in around the clock, renewing on a fixed
timer overnight and at weekends. Now, once a firm has nothing open, nothing
pending and nothing left to trade before its next session for a random
15–45 minutes, its client disconnects and the dashboard shows it Resting.
It logs back in a random 20–50 minutes before the next session opens, at a
check-in every 3–7 Central daytime hours, or at once when trading starts, a
manual leg, copy trade, manual order or AutoBuyer run needs it. Token
renewals fall at random points (Tradovate 15–45 min before expiry, TopstepX
every 45–150 min). Settings → Trading → Rest idle broker sessions
(session_rest) turns it off.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

lib/platform-client.ts

@@ -85,6 +85,10 @@ export interface PlatformClient {
     lastSyncStartedAt?: number;
     /** Whether the broker still shows a working order on the account. */
     hasWorkingOrders?(accountId: number): boolean;
+    /** Why the session can't be logged out now beyond positions and working
+     *  orders — exit pairs it watches, fills or answers it awaits, a report
+     *  fetch underway — or null (session rest, lib/clients.ts). */
+    restBlocker?(): string | null;
     lastFetchErrors: Record<string, string>;
     lastFetchRaw: Record<string, string>;
     recentEntityEvents: { entityType: string; eventType: string; entity: unknown; ts: number }[];