feat: add testing setup in backend

server/src/models/userManager.js

@@ -0,0 +1,16 @@
+import { User, UserProfile } from '@linux-odyssey/models'
+import { hashPassword } from '../utils/auth.js'
+
+export async function createUser(username, email, password) {
+  const user = new User({
+    username,
+    email,
+  })
+  user.hashedPassword = await hashPassword(password)
+  await user.save()
+
+  const userProfile = new UserProfile({
+    user,
+  })
+  await userProfile.save()
+}