Language constants

All UI text must use language constants.

New code

New constants use the current prefix:

COM_JOOMLEAGUE_*

Imported legacy constants

Historical data from the old JoomLeague may contain old constants.

Rule:

• do not delete them;
• do not replace them with hardcoded translated text;
• render them through Text::_();
• add missing translations to the compatibility language layer.

This keeps imports faithful and prevents raw constants from being shown on the frontend.