nidabaser/CRM_Spring_Boot ? reverse-engineered prompt

Build me a simple CRM backend in Spring Boot that matches the README for this repo.

I want a working API for managing customers, offers, expenses, products, categories, interviews, and meetings, with full create, read, update, and delete support for customers. It should let me search customers by email and phone, use PostgreSQL for storage, and have JWT login protection for the private endpoints. Please add clean request and response models, mapping between entities and DTOs, proper error handling, and Swagger so I can explore the API in the browser.

Make it feel like a real small business CRM, with sensible validation and easy to understand endpoints. If anything in the current codebase is incomplete, finish it in a clean way and keep the structure organized. Use the existing project setup, and look up current Spring Boot docs online if you need to.