The gate reported "3/3 passed" while all three builds actually failed (their
rstan dependency would not compile). Root cause: bincraft::build_binary_package()
catches build failures internally and RETURNS "error" for the failed tag instead
of throwing, so the gate's tryCatch never fired and every failed build looked
like a pass -- a false green that would let broken registry entries merge.
Inspect the return value: a tag is a pass only if the (flattened) result is
non-empty and contains no "error" sentinel; a thrown error still counts as
failure. Verified the verdict logic against error/skipped/TRUE/list/NULL/mixed.