Add email notification on new lesson comment

Notify admins/curators (or configured notificationEmails) when a student
leaves a comment under a lesson. New setting notifyOnComment (default on) +
toggle in admin settings. Fires only for student comments, not admin/curator
replies; comment text is HTML-escaped in the email.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/lib/actions/student-actions.ts

@@ -4,7 +4,7 @@ import { prisma } from "@/lib/prisma";
 import { auth } from "@/lib/auth";
 import { headers } from "next/headers";
 import { revalidatePath } from "next/cache";
-import { sendHomeworkSubmittedEmail } from "@/lib/email";
+import { sendHomeworkSubmittedEmail, sendCommentNotificationEmail } from "@/lib/email";
 import { getSettings, parseNotificationEmails, asBool } from "@/lib/settings";
 
 // ── Lesson Progress ───────────────────────────────────────────────────────────
@@ -156,7 +156,7 @@ export async function addComment(lessonId: string, slug: string, text: string, p
 
   const lesson = await prisma.lesson.findUnique({
     where: { id: lessonId },
-    select: { module: { select: { course: { select: { id: true } } } } },
+    select: { title: true, module: { select: { course: { select: { id: true, slug: true } } } } },
   });
   if (!lesson) throw new Error("Lesson not found");
 
@@ -185,6 +185,26 @@ export async function addComment(lessonId: string, slug: string, text: string, p
     data: { lessonId, userId: session.user.id, text: trimmed, ...(parentId ? { parentId } : {}) },
   });
 
+  // Уведомление админам/кураторам о новом комментарии студента (не о своих ответах)
+  if (!isAdmin && !isCurator) {
+    const settings = await getSettings();
+    if (asBool(settings.notifyOnComment)) {
+      const configured = parseNotificationEmails(settings.notificationEmails);
+      const recipients = configured.length > 0
+        ? configured.map((email) => ({ email, name: "" }))
+        : await prisma.user.findMany({
+            where: { role: { in: ["admin", "curator"] } },
+            select: { email: true, name: true },
+          });
+      const lessonUrl = `${process.env.BETTER_AUTH_URL ?? "https://school.second-brain.ru"}/courses/${slug}/lessons/${lessonId}`;
+      await Promise.all(
+        recipients.map((r) =>
+          sendCommentNotificationEmail(r.email, r.name, session.user.name, lesson.title, trimmed, lessonUrl)
+        )
+      );
+    }
+  }
+
   revalidatePath(`/courses/${slug}/lessons/${lessonId}`);
 }