phase-1: optimize code

src/market/YahooClient.js

@@ -0,0 +1,40 @@
+import YahooFinance from 'yahoo-finance2';
+
+export class YahooClient {
+  constructor() {
+    // Instantiate the client as required by v3
+    this.yf = new YahooFinance({
+      suppressNotices: ['yahooSurvey'],
+    });
+  }
+
+  async fetchSummary(ticker, retries = 3, backoff = 1000) {
+    for (let i = 0; i < retries; i++) {
+      try {
+        return await this.yf.quoteSummary(ticker, {
+          modules: [
+            'assetProfile',
+            'financialData',
+            'defaultKeyStatistics',
+            'price',
+            'summaryDetail',
+          ],
+        });
+      } catch (error) {
+        if (i === retries - 1) throw error;
+        await new Promise((res) => setTimeout(res, backoff * (i + 1)));
+      }
+    }
+  }
+
+  // Fetches upcoming earnings dates, ex-dividend date, and dividend date for a ticker.
+  // Returns null on failure so callers can skip gracefully.
+  async fetchCalendarEvents(ticker) {
+    try {
+      const r = await this.yf.quoteSummary(ticker, { modules: ['calendarEvents'] });
+      return r.calendarEvents ?? null;
+    } catch {
+      return null;
+    }
+  }
+}