Stable chn_-prefixed external id (e.g. "chn_solana"). Self-custody WALLET
payment instruments store this in their provider column to reference the
settling chain.
Canonical lowercase chain id (e.g. "solana", "avalanche-c-chain").
Display label (e.g. "Solana").
Execution runtime, or null for chains we don't classify yet.
Service-layer projection of an ACTIVE
b2b.chainrow.