phase-8f: persistant cache locally

server/controllers/finance.controller.ts

@@ -13,10 +13,6 @@ export class FinanceController {
     private readonly advisor: PortfolioAdvisor,
   ) {}
 
-  private static normalizeYahoo(ticker: string): string {
-    return ticker.toUpperCase().replace(/\./g, '-');
-  }
-
   register(app: FastifyInstance): void {
     app.get('/api/finance/portfolio', this.portfolio.bind(this));
     app.post('/api/finance/holdings', { schema: holdingSchema }, this.addHolding.bind(this));
@@ -38,7 +34,7 @@ export class FinanceController {
 
     const screenable = holdings
       .filter((h) => (h.type ?? 'stock') !== 'crypto')
-      .map((h) => FinanceController.normalizeYahoo(h.ticker));
+      .map((h) => h.ticker.toUpperCase());
 
     const results =
       screenable.length > 0