Write SQL for basic user metrics

You are given a simplified schema for a fictional social app called **Nextagram**: - **users**(user_id PK, username, created_at TIMESTAMP) - **follows**(follower_user_id, followed_user_id, created_at TIMESTAMP) - each row means `follower_user_id` follows `followed_user_id` Assume `created_at` is a timestamp (timezone handling is ignored for this part). Write SQL queries to answer: 1) How many users are there? 2) In which **month** did the most users join? (Return the month and the count.) 3) What is the username of the user with the **most followers**? (If there is a tie, return all tied users.)