refactor: update authentication flow to use NextAuth, replace better-auth with axios for API calls, and clean up unused code

lib/types/user.ts

@@ -0,0 +1,38 @@
+import type { ISODateString } from "next-auth";
+
+export interface Permission {
+	id: number;
+	name: string;
+	user: User;
+}
+
+export interface TAuthUser {
+	expiry?: string;
+	token?: string;
+	user: User;
+}
+
+export interface User {
+	id: number;
+	username: string;
+	email: string;
+	user_permissions: Permission[];
+	first_name: string;
+	last_name: string;
+	is_superuser: boolean;
+	date_joined: string;
+	last_login: string;
+}
+
+export interface Session {
+	user?: {
+		token?: string;
+		name?: string | null;
+		email?: string | null;
+		image?: string | null;
+		user?: User & {
+			expiry?: string;
+		};
+	};
+	expires: ISODateString;
+}