Mirror the crafter-build pipeline in a plain GNU Makefile — precompile
the libc++ std module and the Imsd partitions in dependency order,
archive imsd-core, link the three executables with the same clang/
libc++ flags — so distributions can build from source without
packaging crafter-build first. make check runs the same 7 suites;
make install stages the binaries plus the packaging/ files under
DESTDIR/PREFIX.
Rewrite packaging/APKBUILD from a documentation skeleton into a real
source-build APKBUILD on top of it (Alpine's llvm-runtimes ships the
std module sources since 22.x). project.cpp remains the canonical
build description.
Assisted-by: Claude:claude-fable-5
