feat: tokens, shell, healthz

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

app/layout.tsx

@@ -0,0 +1,9 @@
+import type { Metadata, Viewport } from "next";
+import "./globals.css";
+
+export const metadata: Metadata = { title: "SQL Server qAI", description: "Query plan triage, ranked by Jev." };
+export const viewport: Viewport = { width: "device-width", initialScale: 1 };
+
+export default function Root({ children }: { children: React.ReactNode }) {
+  return <html lang="en"><body>{children}</body></html>;
+}