Add homework system (admin, student, curator)

Admin:
- HomeworkEditor in lesson page: create/update/delete assignment description

Student:
- HomeworkSection in lesson page: view assignment, submit text + files
- Resubmission allowed until curator gives feedback
- Shows feedback from curator with date and name

Curator:
- New layout with Second Brain dark sidebar (replaces green theme)
- /curator/dashboard: stats cards (pending, total, reviewed this week)
- /curator/homework: list of all submissions, pending highlighted
- /curator/homework/[id]: review submission, write feedback, redirect after send

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

src/app/curator/dashboard/page.tsx

@@ -1,43 +1,57 @@
 import { headers } from "next/headers";
 import { auth } from "@/lib/auth";
 import { redirect } from "next/navigation";
-import { LogoutButton } from "@/components/layout/logout-button";
+import { prisma } from "@/lib/prisma";
+import Link from "next/link";
 
 export default async function CuratorDashboard() {
   const session = await auth.api.getSession({ headers: await headers() });
-
   if (!session) redirect("/login");
-  if (session.user.role !== "curator" && session.user.role !== "admin") {
-    redirect("/dashboard");
-  }
+
+  const [pending, total, recentFeedbacks] = await Promise.all([
+    prisma.homeworkSubmission.count({ where: { feedbacks: { none: {} } } }),
+    prisma.homeworkSubmission.count(),
+    prisma.homeworkFeedback.count({
+      where: {
+        createdAt: { gte: new Date(Date.now() - 7 * 24 * 60 * 60 * 1000) },
+        curatorId: session.user.id,
+      },
+    }),
+  ]);
 
   return (
-    <div className="min-h-screen bg-green-50">
-      <header className="bg-white border-b border-green-100 px-6 py-4 flex items-center justify-between">
-        <h1 className="text-xl font-bold text-green-900">Second Brain — Куратор</h1>
-        <div className="flex items-center gap-4">
-          <span className="text-sm text-gray-600">{session.user.name}</span>
-          <LogoutButton />
+    <div className="p-8 max-w-3xl">
+      <h1 className="text-2xl font-bold mb-1">Обзор</h1>
+      <p className="text-sm mb-8" style={{ color: "var(--muted-foreground)" }}>Панель куратора</p>
+
+      <div className="grid grid-cols-3 gap-4 mb-8">
+        <StatCard label="Ожидают проверки" value={pending} accent={pending > 0} />
+        <StatCard label="Всего сдано" value={total} />
+        <StatCard label="Проверено за 7 дней" value={recentFeedbacks} />
+      </div>
+
+      {pending > 0 ? (
+        <Link href="/curator/homework" className="btn-aubade btn-aubade-accent inline-flex items-center gap-2 px-5 py-2.5 text-sm">
+          Перейти к проверке ({pending}) →
+        </Link>
+      ) : (
+        <div className="card-aubade p-8 text-center">
+          <p className="text-3xl mb-2">✓</p>
+          <p className="font-bold">Все работы проверены</p>
+          <p className="text-sm mt-1" style={{ color: "var(--muted-foreground)" }}>Новых заданий нет</p>
         </div>
-      </header>
-      <main className="max-w-4xl mx-auto px-6 py-10">
-        <h2 className="text-2xl font-semibold text-gray-800 mb-2">
-          Панель куратора
-        </h2>
-        <p className="text-gray-500 mb-8">Здесь будут домашние задания на проверку.</p>
-        <div className="grid grid-cols-1 md:grid-cols-2 gap-4">
-          <div className="bg-white rounded-2xl border border-green-100 p-6">
-            <p className="text-3xl mb-2">📝</p>
-            <p className="font-medium text-gray-800">Домашние задания</p>
-            <p className="text-sm text-gray-400 mt-1">Новых заданий нет</p>
-          </div>
-          <div className="bg-white rounded-2xl border border-green-100 p-6">
-            <p className="text-3xl mb-2">👥</p>
-            <p className="font-medium text-gray-800">Мои ученики</p>
-            <p className="text-sm text-gray-400 mt-1">Откроется в Этапе 3</p>
-          </div>
-        </div>
-      </main>
+      )}
+    </div>
+  );
+}
+
+function StatCard({ label, value, accent }: { label: string; value: number; accent?: boolean }) {
+  return (
+    <div className="card-aubade p-4">
+      <p className="text-3xl font-bold" style={{ color: accent ? "oklch(0.577 0.245 27.325)" : "var(--foreground)" }}>
+        {value}
+      </p>
+      <p className="text-xs mt-1 uppercase tracking-widest" style={{ color: "var(--muted-foreground)" }}>{label}</p>
     </div>
   );
 }