Initial commit — AI-powered coding tutor (Professor)

Next.js 16, React 19, Monaco editor, Anthropic SDK, multi-provider AI,
Wandbox Python execution, iframe HTML preview, SQLite auth + session persistence.

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

app/page.tsx

@@ -0,0 +1,5 @@
+import AppShell from '@/components/AppShell';
+
+export default function Home() {
+  return <AppShell />;
+}