If you move all HAL libraries into a folder by the name of your project, and additionally have a header file in that folder which includes all used HAL libraries. You could distribute that folder alone.
Imaginative folder structure:/ProjectName
Make ProjectName.h look like:
Now all your code can include ProjectName.h
[ I do not know if this works with the Arduino IDE, but it ought to ]
Great looking project! Glad you found the HALs useful