feat: build Lead Workspace page with KPIs, source grid, lead cards, and sidebar widgets

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/components/leads/alerts-widget.tsx

@@ -0,0 +1,30 @@
+import { daysAgoFromNow } from '@/lib/format';
+import type { Lead } from '@/types/entities';
+
+interface AlertsWidgetProps {
+    leads: Lead[];
+}
+
+export const AlertsWidget = ({ leads }: AlertsWidgetProps) => {
+    const agingCount = leads.filter(
+        (l) =>
+            l.leadStatus === 'NEW' &&
+            l.createdAt !== null &&
+            daysAgoFromNow(l.createdAt) > 5,
+    ).length;
+
+    if (agingCount === 0) {
+        return null;
+    }
+
+    return (
+        <div className="rounded-xl border border-error-subtle bg-error-primary p-4">
+            <p className="text-xs font-bold text-error-primary">
+                {agingCount} leads aging &gt; 5 days
+            </p>
+            <p className="mt-1 text-xs text-error-primary opacity-80">
+                These leads haven&apos;t been contacted and are at risk of going cold.
+            </p>
+        </div>
+    );
+};