COLLECT_SRC_FILES only globs compiled and header extensions, so two files of the
public include tree never joined INC_LIST: bq_log/misc/bq_log_c_api.inc, which
bq_log_c_api.h includes, and bq_log/bq.log.cppm, the C++20 module entry. The Xcode
framework build derives Headers/ from INC_LIST alone (GROUP_FOR_IDE sets
MACOSX_PACKAGE_LOCATION only for that list), so every iOS and macOS framework has
shipped without them: the C API header cannot be compiled from a framework at all,
and 'import bq.log;' has no module unit to build.

Add both extensions to INC_LIST, header-only, before GROUP_FOR_IDE. Every other
package shape (the include/ trees, the Android AAR prefab, the Unreal plugin)
copies the include directory wholesale and was never affected.