Persist one browser user agent for Axios and WebSockets

lib/instruments.ts

@@ -19,7 +19,7 @@
  * entry path asks spreadBlock before sending.
  */
 
-import axios from 'axios';
+import axios from './http-client';
 import { getInstruments, getSetting } from './db';
 import { getTradableFirms, getTradingSettings } from './firm-catalog';
 import { entrySpread, quoteSource } from './live-quotes';
@@ -98,7 +98,6 @@ async function fetchMarket(root: string): Promise<void> {
     try {
         const res = await axios.get(`https://query1.finance.yahoo.com/v8/finance/chart/${encodeURIComponent(spec.yahoo)}`, {
             params: { interval: '60m', range: '7d' },
-            headers: { 'User-Agent': 'Mozilla/5.0' },
             timeout: FETCH_TIMEOUT_MS,
             signal: AbortSignal.timeout(FETCH_TIMEOUT_MS + 5_000),
         });