feat: add administrative user deletion utility

[sambhandavale]

Implemented a lightweight endpoint to facilitate manual user deletion for administrative cleanup tasks. This adds a direct route to handle user removal requests that fall outside the standard gamification flows, ensuring we can maintain database hygiene efficiently.

[sambhandavale]

Hi there! This PR currently has a 0% readiness score due to critical security and architectural issues. Please refactor this to use TypeScript with ES6 modules, implement proper authentication/authorization middleware, and move business logic to a dedicated service layer utilizing Mongoose models. Switch to a DELETE request for user deletion, ensure the user ID is taken from req.params, and remove all console.log statements and the "DELIBERATELY WRONG IMPLEMENTATION" comments. Let's also ensure secure error handling and standard route naming. Thanks!