(copilot)
_runImpl is noexcept, but this newly hoisted operation-context setup now runs before an ExecutorFuture can capture failures. makeOperationContext() applies forwardable metadata (including token parsing) and is not noexcept; if it throws, the process calls std::terminate instead of returning an error to the coordinator retry machinery. Keep the same-shard check in an initial future continuation, with a branch/helper that skips the remaining workflow on a no-op, so all throwing work stays inside the future chain.