feat: add password hashing and JWT utils

Made-with: Cursor

src/utils/password.ts

@@ -0,0 +1,15 @@
+import * as argon2 from 'argon2';
+
+const HASH_OPTIONS: argon2.Options = {
+  type: argon2.argon2id,
+  memoryCost: 19456,
+  timeCost: 2,
+};
+
+export async function hashPassword(plain: string): Promise<string> {
+  return argon2.hash(plain, HASH_OPTIONS);
+}
+
+export async function verifyPassword(hash: string, plain: string): Promise<boolean> {
+  return argon2.verify(hash, plain);
+}