The pinned BUILD_SOURCES are the a135252 qualification build inputs.
generate_config hashes the whole kernel snapshot, so after K1/K2 the
working-tree kernels (legitimately) no longer reproduce them. The test
now archives src/CelerisLab/lbm/kernels at NUMERICAL_REVISION and points
compiler_v2._KERNEL_DIR there; config headers are still rendered by
today's compiler. BUILD_SOURCES and the equality assertion are unchanged;
each size is a subTest; a missing NUMERICAL_REVISION fails (no skip).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>