Add quick enroll button to admin users table

Adds a "+ Доступ" button to each user row in the admin users table.
Clicking it opens a centered modal with a course dropdown, optional
expiry date, and a Server Action that upserts CourseEnrollment, logs
to AccessLog, and sends sendCourseAccessEmail on new enrollments.

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

src/app/admin/users/enroll-action.ts

@@ -0,0 +1,75 @@
+"use server";
+
+import { prisma } from "@/lib/prisma";
+import { headers } from "next/headers";
+import { auth } from "@/lib/auth";
+import { sendCourseAccessEmail } from "@/lib/email";
+import { revalidatePath } from "next/cache";
+
+async function requireAdmin() {
+  const session = await auth.api.getSession({ headers: await headers() });
+  if (!session || session.user.role !== "admin") throw new Error("Forbidden");
+  return session;
+}
+
+export async function grantCourseAccess(
+  userId: string,
+  courseId: string,
+  expiresAt: Date | null
+): Promise<{ ok: true } | { error: string }> {
+  try {
+    const session = await requireAdmin();
+
+    const [user, course] = await Promise.all([
+      prisma.user.findUnique({ where: { id: userId }, select: { email: true, name: true } }),
+      prisma.course.findUnique({ where: { id: courseId }, select: { title: true } }),
+    ]);
+
+    if (!user) return { error: "Пользователь не найден" };
+    if (!course) return { error: "Курс не найден" };
+
+    const existing = await prisma.courseEnrollment.findUnique({
+      where: { userId_courseId: { userId, courseId } },
+    });
+
+    await prisma.courseEnrollment.upsert({
+      where: { userId_courseId: { userId, courseId } },
+      update: { expiresAt },
+      create: { userId, courseId, expiresAt },
+    });
+
+    await prisma.accessLog.create({
+      data: {
+        courseId,
+        userId,
+        action: "granted",
+        method: "quick",
+        grantedById: session.user.id,
+      },
+    });
+
+    // Send email only on new enrollment (not on update)
+    if (!existing) {
+      await sendCourseAccessEmail(user.email, user.name ?? user.email, course.title).catch(
+        (e) => console.error("[enroll-action] sendCourseAccessEmail:", e)
+      );
+    }
+
+    revalidatePath("/admin/users");
+    revalidatePath(`/admin/users/${userId}`);
+
+    return { ok: true };
+  } catch (e) {
+    console.error("[enroll-action] grantCourseAccess:", e);
+    return { error: "Произошла ошибка. Попробуйте ещё раз." };
+  }
+}
+
+export async function getPublishedCourses(): Promise<{ id: string; title: string }[]> {
+  await requireAdmin();
+  return prisma.course.findMany({
+    where: { published: true },
+    select: { id: true, title: true },
+    orderBy: { title: "asc" },
+  });
+}