v2.0.2: Bugfixes

This release contains changes associated with these GitHub issues:

#221: E_USER_ERROR is deprecated in PHP 8.4.
#222: Can't remove a DbIo template, once created.
#223: Remove zc1.3.x-era boxes file and subdirectory.
#224: Initialize inserted categories' sort-order to 0 (was null).
#225: Correct DbIoOptionsValuesHandler, was creating uneditable option-values.
#226: Pre-define all class properties in the DbIoHandler class.
#238: Remove unwanted centered-text styling from the customization tool.
#239: Add links to the GitHub wiki in the main admin tools' instructions.