Release Notes v1.4.0: Laravel TenantScope Database Isolation

We are proud to release Solidrix Send v1.4.0, which introduces full multi-tenant support for enterprise agencies and product teams. ### Features Included: - **TenantScope DB Isolation**: Complete database level security ensuring configuration data is strictly separated by Brand/Organization. - **Sub-user Management**: Grant clients access to their respective brand dashboards without exposing global infrastructure settings. - **Custom Brand Switcher**: Switch contexts inside the app with a single click.