I’m looking for CRM solutions that are self-hosted and completely open-source, where I can access the entire source code. I want a platform that allows me to customize every aspect, from workflows and modules to integrations and UI, to my business needs. Which self-hosted CRM solutions, such as SuiteCRM, Odoo, Krayin CRM, EspoCRM, or Vtiger, offer this level of flexibility and control, allowing developers to modify, extend, and customise the system without restrictions?