"""The TUI frontend for the audiobook generator.

``ui.tui`` is the DOS-style curses widget library, and ``ui.hub`` is the
main menu the user sees when running ``audiobook.py`` with no arguments
(set up/configure backends, convert the input directory). It is the only
entry point for the interactive workflow; everything else under
``backends/`` and ``converter/`` is library code driven by it or by the
``audiobook.py`` CLI flags.
"""