The Debian 12 (Bookworm) packaging keeps the upstream FetchContent FTXUI
fallback enabled because Bookworm does not provide libftxui-dev in the main
archive.

The package rules pin CMake to Qt5 with Qt5_DIR so the build remains on the
Qt5 stack even when a newer Qt major version is also installed locally.

This packaging tree uses source format 3.0 (native) so crossbuilder can create
its timestamped local source package without requiring an upstream orig tarball
from an APT source repository.
