Downgrade to NextAuth v4 to fix constructor error

pages/api/auth/[...nextauth].ts

@@ -0,0 +1,52 @@
+import NextAuth from "next-auth"
+import CredentialsProvider from "next-auth/providers/credentials"
+import { prisma } from "@/lib/db"
+import bcrypt from "bcryptjs"
+import { z } from "zod"
+
+const loginSchema = z.object({
+  email: z.string().email(),
+  password: z.string().min(1),
+})
+
+export default NextAuth({
+  providers: [
+    CredentialsProvider({
+      name: "credentials",
+      credentials: {
+        email: { label: "Email", type: "email" },
+        password: { label: "Password", type: "password" },
+      },
+      async authorize(credentials) {
+        try {
+          const { email, password } = loginSchema.parse(credentials)
+          const user = await prisma.user.findUnique({ where: { email } })
+          
+          if (!user || !user.passwordHash) return null
+          
+          const isValid = await bcrypt.compare(password, user.passwordHash)
+          if (!isValid) return null
+          
+          return { id: user.id, email: user.email, name: user.name }
+        } catch {
+          return null
+        }
+      },
+    }),
+  ],
+  session: { strategy: "jwt" },
+  pages: {
+    signIn: "/auth/login",
+    error: "/auth/error",
+  },
+  callbacks: {
+    async jwt({ token, user }) {
+      if (user) token.id = user.id
+      return token
+    },
+    async session({ session, token }) {
+      if (token.id) session.user.id = token.id
+      return session
+    },
+  },
+})