Companion to luxfi/runtime: the field on the embedded Runtime struct
is the primary network's UTXO fee asset (P+X), not X-chain-specific.
Rename consensus consumers + test helpers to match.
Includes the local runtime replace temporarily — drop once
luxfi/runtime tags a release with the rename.
Define Element, Requests, and SharedMemory types locally in
runtime package instead of importing from vm/chains/atomic.
This breaks the import cycle:
consensus → vm → consensus
zeekay
