Consolidate server utilities into shared module

- Add lib/server/utils/normalize.ts with normalizeTicker, normalizeTagsOrNull, nowIso, todayIso
- Add lib/server/utils/validation.ts with asRecord, asBoolean, asStringArray, asEnum
- Add lib/server/utils/index.ts re-exporting all utilities
- Remove duplicate lib/server/utils.ts (old file)
- Update all repos and files to use shared utilities
- Remove redundant ?? '' from normalizeTicker calls
- Update watchlist.ts to use normalizeTagsOrNull for null-return tags

lib/server/prices.ts

@@ -1,3 +1,5 @@
+import { normalizeTicker } from '@/lib/server/utils';
+
 const YAHOO_BASE = 'https://query1.finance.yahoo.com/v8/finance/chart';
 const QUOTE_CACHE_TTL_MS = 1000 * 60;
 const PRICE_HISTORY_CACHE_TTL_MS = 1000 * 60 * 15;
@@ -27,11 +29,11 @@ const quoteCache = new Map<string, QuoteCacheEntry>();
 const priceHistoryCache = new Map<string, PriceHistoryCacheEntry>();
 
 function buildYahooChartUrl(ticker: string, params: string) {
-  return `${YAHOO_BASE}/${encodeURIComponent(ticker.trim().toUpperCase())}?${params}`;
+  return `${YAHOO_BASE}/${encodeURIComponent(normalizeTicker(ticker))}?${params}`;
 }
 
 export async function getQuote(ticker: string): Promise<QuoteResult> {
-  const normalizedTicker = ticker.trim().toUpperCase();
+  const normalizedTicker = normalizeTicker(ticker);
   const cached = quoteCache.get(normalizedTicker);
 
   if (cached && cached.expiresAt > Date.now()) {
@@ -101,7 +103,7 @@ export async function getQuoteOrNull(ticker: string): Promise<number | null> {
 }
 
 export async function getHistoricalClosingPrices(ticker: string, dates: string[]) {
-  const normalizedTicker = ticker.trim().toUpperCase();
+  const normalizedTicker = normalizeTicker(ticker);
   const normalizedDates = dates
     .map((value) => {
       const parsed = Date.parse(value);
@@ -169,7 +171,7 @@ export async function getHistoricalClosingPrices(ticker: string, dates: string[]
 }
 
 export async function getPriceHistory(ticker: string): Promise<PriceHistoryResult> {
-  const normalizedTicker = ticker.trim().toUpperCase();
+  const normalizedTicker = normalizeTicker(ticker);
   const cached = priceHistoryCache.get(normalizedTicker);
 
   if (cached && cached.expiresAt > Date.now()) {