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/task-processors.ts

@@ -39,6 +39,7 @@ import {
 } from '@/lib/server/sec';
 import { enqueueTask } from '@/lib/server/tasks';
 import { hydrateFilingTaxonomySnapshot } from '@/lib/server/taxonomy/engine';
+import { nowIso } from '@/lib/server/utils';
 
 const EXTRACTION_REQUIRED_KEYS = [
   'summary',
@@ -762,7 +763,7 @@ async function processSyncFilings(task: Task) {
       await deleteCompanyFinancialBundlesForTicker(filing.ticker);
       taxonomySnapshotsHydrated += 1;
     } catch (error) {
-      const now = new Date().toISOString();
+      const now = nowIso();
       await upsertFilingTaxonomySnapshot({
         filing_id: filing.id,
         ticker: filing.ticker,
@@ -961,7 +962,7 @@ async function processRefreshPrices(task: Task) {
       }
     }
   );
-  const updatedCount = await applyRefreshedPrices(userId, quotes, new Date().toISOString());
+  const updatedCount = await applyRefreshedPrices(userId, quotes, nowIso());
 
   const result = {
     updatedCount,