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/api/rss/feeds/route.ts

@@ -4,6 +4,13 @@ import Parser from 'rss-parser';
 
 export const dynamic = 'force-dynamic';
 
+function normalizeDate(item: { isoDate?: string; pubDate?: string }): string | null {
+    const raw = item.isoDate || item.pubDate;
+    if (!raw) return null;
+    const d = new Date(raw);
+    return isNaN(d.getTime()) ? null : d.toISOString();
+}
+
 export async function GET() {
     const db = await getDb();
     const feeds = await db.all(`
@@ -56,7 +63,7 @@ export async function POST(req: NextRequest) {
                 feedId,
                 item.title,
                 item.link,
-                item.pubDate || item.isoDate || null,
+                normalizeDate(item),
                 item.creator || item.author || null,
                 (item.contentSnippet || item.content || '').substring(0, 500) || null
             );