refactor: migrate authentication system and update Drizzle schema.

src/lib/auth.ts

@@ -0,0 +1,31 @@
+import { betterAuth } from "better-auth";
+import { drizzleAdapter } from "better-auth/adapters/drizzle";
+import { nextCookies } from "better-auth/next-js";
+import { db } from "~/server/db";
+import * as schema from "~/server/db/schema";
+
+export const auth = betterAuth({
+    database: drizzleAdapter(db, {
+        provider: "pg",
+        schema: {
+            user: schema.users,
+            session: schema.sessions,
+            account: schema.accounts,
+            verification: schema.verificationTokens,
+        },
+    }),
+    emailAndPassword: {
+        enabled: true,
+        password: {
+            hash: async (password) => {
+                const bcrypt = await import("bcryptjs");
+                return bcrypt.hash(password, 12);
+            },
+            verify: async ({ hash, password }) => {
+                const bcrypt = await import("bcryptjs");
+                return bcrypt.compare(password, hash);
+            },
+        },
+    },
+    plugins: [nextCookies()],
+});