PUBLIC_NODE_IDS only checked that every listed id was still registered. A
brand-new id could register and validation stayed green, so the release gate
could not tell when a node reached the public pack without anyone deciding it
should ship.
Also pins SimpleWatermarkRemover in its own LEGACY_NODE_IDS set. It is the
pre-convention id kept so already-published workflows keep loading, and it was
never listed - so the new check now asserts the compatibility shim is present
rather than flagging it as a stray.
ausboss
e152b903e0