Fix Performance page showing empty data

The trends and snapshots endpoints returned periodLabel ("last_30_days")
as the date field, which parseISO() couldn't parse, causing all records
to be filtered out. Now uses capturedAt timestamp for date filtering and
display.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

apps/api/src/routes/performance.ts

@@ -123,6 +123,7 @@ export default async function (fastify: FastifyInstance) {
       const rows = await db
         .select({
           date: performanceSnapshots.periodLabel,
+          capturedAt: performanceSnapshots.capturedAt,
           platformId: performanceSnapshots.platformId,
           viewsSearch: performanceSnapshots.viewsSearch,
           viewsListing: performanceSnapshots.viewsListing,

apps/frontend/src/pages/Performance.tsx

@@ -206,7 +206,7 @@ export default function Performance() {
 
   const trends: TrendPoint[] = rawTrends?.length
     ? rawTrends.map((r: any) => ({
-        date: r.date || r.periodLabel,
+        date: r.capturedAt ? r.capturedAt.split('T')[0].split(' ')[0] : r.date || r.periodLabel,
         platform: r.platformId || r.platform,
         views_search: Number(r.viewsSearch ?? r.views_search ?? 0),
         conversion_rate: Number(r.conversionRate ?? r.conversion_rate ?? 0),
@@ -217,7 +217,7 @@ export default function Performance() {
     : MOCK_TRENDS;
   const snapshots: SnapshotRow[] = rawSnapshots?.length
     ? rawSnapshots.map((r: any) => ({
-        date: r.periodLabel || r.date,
+        date: r.capturedAt ? r.capturedAt.split('T')[0].split(' ')[0] : r.periodLabel || r.date,
         platform: r.platformId || r.platform,
         views: Number(r.viewsSearch ?? r.views ?? 0),
         clicks: Number(r.viewsListing ?? r.clicks ?? 0),