flatten app to repo root and update docker deployment for single-stack runtime

app/api/portfolio/insights/latest/route.ts

@@ -0,0 +1,10 @@
+import { getStoreSnapshot } from '@/lib/server/store';
+
+export async function GET() {
+  const snapshot = await getStoreSnapshot();
+  const insight = snapshot.insights
+    .slice()
+    .sort((a, b) => Date.parse(b.created_at) - Date.parse(a.created_at))[0] ?? null;
+
+  return Response.json({ insight });
+}