Polish UX: auto-redirect on create, fix design consistency

- createModule now redirects to module page after creation
- createLesson now redirects to lesson editor after creation
- Regenerate Prisma client to fix missing types (category, accessLog, expiresAt)
- Rewrite sortable-modules/lessons with Second Brain design tokens (remove amber/slate)
- Rewrite lesson-editor toolbar and toggle with design tokens
- Fix register page/form: replace amber theme with card-aubade design

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

src/app/admin/courses/[courseId]/actions.ts

@@ -4,6 +4,7 @@ import { prisma } from "@/lib/prisma";
 import { headers } from "next/headers";
 import { auth } from "@/lib/auth";
 import { revalidatePath } from "next/cache";
+import { redirect } from "next/navigation";
 
 async function requireAdmin() {
   const session = await auth.api.getSession({ headers: await headers() });
@@ -17,8 +18,9 @@ export async function createModule(courseId: string, formData: FormData) {
   await requireAdmin();
   const title = formData.get("title") as string;
   const count = await prisma.module.count({ where: { courseId } });
-  await prisma.module.create({ data: { courseId, title, order: count } });
+  const mod = await prisma.module.create({ data: { courseId, title, order: count } });
   revalidatePath(`/admin/courses/${courseId}`);
+  redirect(`/admin/courses/${courseId}/modules/${mod.id}`);
 }
 
 export async function updateModule(moduleId: string, courseId: string, formData: FormData) {