Fix RSS time filters and add draggable grid layout

Normalize pub_date to ISO 8601 on insert so SQLite datetime comparisons
work correctly. Migrate existing RFC 2822 dates. Change 1h filter to 12h.
Add react-grid-layout with persistent drag/resize and reset button.

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

app/page.tsx

@@ -7,15 +7,10 @@ import { NewsFeed } from "@/components/widgets/NewsFeed";
 export default function Home() {
   return (
     <GridShell>
-      {/* Row 1 */}
-      <UptimeCard />
-      <WeatherCard />
-
-      {/* Row 1 & 2 (Globe spans 2 rows) */}
-      <GlobeCard />
-
-      {/* Row 2-4: NewsFeed spans 4 cols, 3 rows */}
-      <NewsFeed />
+      <div key="uptime"><UptimeCard /></div>
+      <div key="weather"><WeatherCard /></div>
+      <div key="globe"><GlobeCard /></div>
+      <div key="newsfeed"><NewsFeed /></div>
     </GridShell>
   );
 }