MLM Referral Engine Overhaul – Scaling from 2-Level to 4-Level Structure

Redesigned core commission logic, binary payout rules, and user hierarchy visualization in a Laravel-based MLM platform — improving scalability, accuracy, and user transparency.

Key Changes Implemented:
- Extended referral tree depth from 2 → 4 direct levels
- Rewrote referral commission calculation engine (dynamic % per level)
- Updated binary commission logic to support 4-level matching & spillover
- Modified user hierarchy API endpoints (Laravel Eloquent + recursive queries)
- Redesigned frontend tree visualization (Bootstrap + custom JS) to dynamically render 4-level structures.
- Added real-time commission preview & admin validation rules