Variable MUSD_CONTRACT_NAMES`Const`

MUSD_CONTRACT_NAMES: readonly [
    "borrowerOperations",
    "troveManager",
    "sortedTroves",
    "hintHelpers",
    "priceFeed",
    "interestRateManager",
    "musd",
] = ...

Every contract the SDK resolves, in one place. This is the authority for BOTH the completeness check and the unknown-key rejection, so the two cannot drift apart: a contract added here is immediately required by one and accepted by the other.