Persist one browser user agent for Axios and WebSockets

README.md

@@ -184,7 +184,24 @@ It is read-only unless `DX_CONFIRM=yes DX_ACCOUNT=<code>` are set too, which
 adds one minimum-size live round trip.
 
 `npm run check` runs the pure-logic checks (fees, stops, sizing, trading
-hours, the DXtrade selector, the futures draw and instrument lists).
+hours, the DXtrade selector, the futures draw and instrument lists), plus local
+HTTP/WebSocket checks against a temporary database.
+
+### Outbound user agent
+
+On first server load, each instance randomly selects a desktop Chrome,
+Firefox, or Edge user agent and saves it as `user_agent` in its settings.
+Settings → Network shows the selected value. It stays the same across requests,
+WebSocket reconnects, page reloads, and server restarts, and travels with backups.
+An existing saved value is reused; an absent or blank value is generated automatically.
+
+All server Axios calls use `lib/http-client.ts`; import Axios from
+`@/lib/http-client` when adding requests. Its defaults and interceptor also apply
+to `axios.create()` clients, so per-request headers cannot accidentally replace
+the saved user agent. ESLint rejects direct application imports of the Axios package.
+Use `brokerWebSocket` or `signalrWebSocket` from `lib/outbound-proxy.ts` for broker
+sockets, and `directWebSocket` for control sockets. All share the same user agent;
+the broker proxy still applies only to broker traffic.
 
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