720/723/727/743 -> test/asm/callarg_test.ww. Ordered PUSHQ windows,
tag-synth + stack-overflow-cleanup needles and the variadic
eightbyte store-count floors preserved. Strengthened: 720's
4-variant row gains the byte-id leg the C skipped behind the
then-open #22 zero-init gate — #22 landed (724 pins the fix), and
the leg verifies green on both stages.
