ConstThe stages a strip of this KIND carries, in canonical (default) order — the vocabulary the row's codec publishes and the list an override must be a permutation of.
Derived from the channel contract, never from a hand-kept list beside it: each native stage
kind is spelled the same as the import('./channel-contract.js').ChannelFact that
declares it, so contractDeclares is the one answer to "does this kind have a comp".
The DEFAULT order for a kind —
mix_order.h'somx_order_default()sequence, restricted to the stages this kind has. Derived on every read: a channel with no override reads this, and a session that never reordered carries no block (derive, never store the derivation).