Addresses are env-sourced so ops can rotate mainnet/testnet deployments
without a code change. Defaults fall back to empty strings so a missing
env surfaces as a clear "not configured" error at call time rather than
silently pointing at the wrong contract.
Stellar Soroban contract addresses + Soroban RPC + quote-server config per network.
Addresses are env-sourced so ops can rotate mainnet/testnet deployments without a code change. Defaults fall back to empty strings so a missing env surfaces as a clear "not configured" error at call time rather than silently pointing at the wrong contract.