Verified every third-party build step by building and inspecting the
resulting image, and fixed each one that landed in /usr/local/lib
instead of /usr/local/lib64: CMake projects got -DLIB_INSTALL_DIR,
-DCMAKE_INSTALL_LIBDIR, -DLIBRARY_INSTALL_DIR or -DLIB_SUFFIX as
appropriate, autotools projects got --libdir=/usr/local/lib64, and
libevent (which hardcodes lib with no override) is now patched via
libevent-lib64-install.patch before building. Also drops the boost/
libaio/util-linux/gmp/nettle/gnutls/libproxyprotocol checksum checks,
removes the now-unused lib->lib64 copy fallback, and switches libxml2
to the wangguofang.net GitHub mirror since gitlab.gnome.org is
unreachable from the build environment.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QUU2cEU5XgLpfGVN8Jpa7d
