furhter bug fixes and updates

discord_verificiation/playtime-frontend/app/api/map-population/route.ts

@@ -1,9 +1,21 @@
 import { NextRequest, NextResponse } from 'next/server';
 import { getMapPopulationSeries } from '@/lib/queries';
+import { formatDbDateTime } from '@/lib/timezone';
 
 export async function GET(req: NextRequest) {
   const limitParam = req.nextUrl.searchParams.get('limit');
+  const beforeParam = req.nextUrl.searchParams.get('before'); // ISO string — page further back for pan-to-load-more
   const limit = Math.min(Math.max(Number(limitParam) || 40, 1), 200);
-  const points = await getMapPopulationSeries(limit);
+
+  let before: string | undefined;
+  if (beforeParam) {
+    const d = new Date(beforeParam);
+    if (Number.isNaN(d.getTime())) {
+      return NextResponse.json({ error: 'invalid before param' }, { status: 400 });
+    }
+    before = formatDbDateTime(d);
+  }
+
+  const points = await getMapPopulationSeries(limit, before);
   return NextResponse.json({ points });
 }