Implement platform settings (Stage 9)

- Wire settings to actual platform behavior: maintenance mode, registration toggle,
  notification emails, curator feedback emails, email verification flag
- Add logo (logoUrl, showLogo) and social network links (YouTube, VK, Telegram) settings
- Show logo + school name dynamically in student layout header
- Add footer to student layout with org requisites and social links
- Register page: read settings server-side, validate terms checkbox with legal links
- Login page: show notice when redirected from closed registration
- Settings form: add Logo and Social Networks sections

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

src/app/curator/homework/[submissionId]/actions.ts

@@ -5,6 +5,7 @@ import { auth } from "@/lib/auth";
 import { headers } from "next/headers";
 import { revalidatePath } from "next/cache";
 import { sendFeedbackReceivedEmail } from "@/lib/email";
+import { getSetting, asBool } from "@/lib/settings";
 
 async function requireCurator() {
   const session = await auth.api.getSession({ headers: await headers() });
@@ -78,14 +79,17 @@ export async function submitFeedback(
   });
 
   const { lesson } = submission.homework;
-  const lessonUrl = `${process.env.BETTER_AUTH_URL ?? "https://school.second-brain.ru"}/courses/${lesson.module.course.slug}/lessons/${lesson.id}`;
-  await sendFeedbackReceivedEmail(
-    submission.user.email,
-    submission.user.name,
-    lesson.title,
-    data.text,
-    lessonUrl
-  );
+  const notifySetting = await getSetting("notifyStudentOnFeedback");
+  if (asBool(notifySetting)) {
+    const lessonUrl = `${process.env.BETTER_AUTH_URL ?? "https://school.second-brain.ru"}/courses/${lesson.module.course.slug}/lessons/${lesson.id}`;
+    await sendFeedbackReceivedEmail(
+      submission.user.email,
+      submission.user.name,
+      lesson.title,
+      data.text,
+      lessonUrl
+    );
+  }
 
   revalidatePath("/curator/homework");
   revalidatePath(`/curator/homework/${submissionId}`);