The field is the primary network's UTXO fee asset (P+X), not
X-chain-specific. P-chain CreateChainTx / AddChainValidatorTx and
X-chain transfers all burn it for fees. Same number on P and X by
construction; the name should reflect the function, not the chain.
Renames applied across:
- wallet/chain/{p,x}/builder.Context.UTXOAssetID
- wallet/chain/x/builder.Backend.UTXOAssetID() trait method
- node/config: resolveUTXOAssetID + nodeConfig.UTXOAssetID
- vms/platformvm + vms/xvm + chains/manager consumers
- examples (deploy-chains, get-p-chain-balance, ...)
Includes local replaces for luxfi/{runtime,consensus} pending their
release tags landing. Drop after upstream tags ship.
Companion PRs: luxfi/runtime#2, luxfi/consensus#11. Downstream
consumers (sdk, cli, genesis, liquidity) follow.