Zotero Customization for Windows & Mac

I need a customized version of Zotero from the GitHub project link provided. The modifications should be functional for both Windows and Mac operating systems. Key Customizations: 1. Remove the "Export Library" function. 2. Implement a "Log In to Start Using" feature, using a standard user and password registration method. 3. Create a system for importing data from an online source, specifically hosted on CPanel. 4. Add support for custom themes to enhance user experience. (JUST change LOGO) Ideal Skills: - Proficiency in cross-platform software development, specifically for Windows and Mac. - Experience with modifying open-source software, particularly from GitHub. - Knowledge of implementing user login systems and data import functionalities. The freelancer should be able to provide a seamless, user-friendly application with the specified customizations. Previous experience with Zotero or similar software is a plus. Please ensure your bid includes your estimated timeline for completing this project.