Initialize Stage 0: Next.js 16 scaffold with auth and role-based routing

- Next.js 16.2.2 + React 19 + TypeScript + Tailwind v4
- Better Auth with email/password and role system (student/curator/admin)
- Prisma 7 schema: User, Session, Account, Verification + full LMS model
- Role-based dashboards: student /dashboard, curator /curator/dashboard, admin /admin/dashboard
- Auth pages: login, register, verify-email
- Better Auth API route handler
- Middleware for route protection
- Docker Compose with PostgreSQL 16
- Seed script with test users (admin/curator/student)
- CLAUDE.md and ROADMAP.md project documentation

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

src/lib/auth.ts

@@ -0,0 +1,36 @@
+import { betterAuth } from "better-auth";
+import { prismaAdapter } from "better-auth/adapters/prisma";
+import { admin } from "better-auth/plugins";
+import { prisma } from "./prisma";
+
+export const auth = betterAuth({
+  database: prismaAdapter(prisma, {
+    provider: "postgresql",
+  }),
+  emailAndPassword: {
+    enabled: true,
+    requireEmailVerification: true,
+  },
+  plugins: [
+    admin({
+      defaultRole: "student",
+      adminRoles: ["admin"],
+    }),
+  ],
+  trustedOrigins: [
+    process.env.BETTER_AUTH_URL ?? "http://localhost:3000",
+    "https://school.second-brain.ru",
+  ],
+  user: {
+    additionalFields: {
+      role: {
+        type: "string",
+        defaultValue: "student",
+        input: false,
+      },
+    },
+  },
+});
+
+export type Session = typeof auth.$Infer.Session;
+export type User = typeof auth.$Infer.Session.user;