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>

components/editor/CodeEditor.tsx

@@ -0,0 +1,46 @@
+'use client';
+
+import dynamic from 'next/dynamic';
+import type { SupportedLanguage } from '@/types';
+
+const MonacoEditor = dynamic(() => import('@monaco-editor/react'), {
+  ssr: false,
+  loading: () => (
+    <div className="flex h-full w-full items-center justify-center bg-[#1e1e1e]">
+      <div className="h-8 w-8 animate-spin rounded-full border-2 border-zinc-600 border-t-blue-400" />
+    </div>
+  ),
+});
+
+interface Props {
+  language: SupportedLanguage;
+  value: string;
+  onChange: (value: string) => void;
+  height?: string;
+}
+
+export default function CodeEditor({ language, value, onChange, height = '100%' }: Props) {
+  const monacoLanguage = language === 'html' ? 'html' : 'python';
+
+  return (
+    <MonacoEditor
+      height={height}
+      language={monacoLanguage}
+      value={value}
+      theme="vs-dark"
+      onChange={(val) => onChange(val ?? '')}
+      options={{
+        fontSize: 14,
+        fontFamily: "'JetBrains Mono', 'Fira Code', 'Cascadia Code', Consolas, monospace",
+        minimap: { enabled: false },
+        scrollBeyondLastLine: false,
+        padding: { top: 16, bottom: 16 },
+        lineNumbersMinChars: 3,
+        tabSize: 4,
+        wordWrap: 'on',
+        smoothScrolling: true,
+        cursorSmoothCaretAnimation: 'on',
+      }}
+    />
+  );
+}