feat: add news sources, 30-day filter, and fix ticker performance

- Fix Al Jazeera RSS URL (feeds.aljazeera.com is dead, moved to www.aljazeera.com)
- Add 8 new RSS sources: DW, France 24, Euronews, DW Africa, RFI, Africa News,
  NYT Africa, NPR — covering Germany, Europe, Africa, Cameroon region, and USA
- Filter WHO outbreak news and ticker feed to last 30 days (drops stale alerts
  like 733-day-old WHO DONs)
- Fix ticker causing Chrome to crash: add will-change:transform and
  contain:layout style for GPU compositing, reduce DOM nodes from 80 to 40
- Add badge styles for new source categories (DW, EU, Africa)

apis/sources/who.mjs

@@ -51,7 +51,11 @@ export async function getOutbreakNews() {
       return db - da;
     });
 
-    return items.map(item => ({
+    // Filter to last 30 days only
+    const cutoff = new Date(Date.now() - 30 * 24 * 60 * 60 * 1000);
+    const recent = items.filter(item => new Date(item.PublicationDate || 0) >= cutoff);
+
+    return recent.map(item => ({
       title: item.Title,
       date: item.PublicationDate,
       donId: item.DonId || null,