Despite a broadly worded delegation clause, a court must always decide whether the parties entered into an arbitration agreement. And, when the defendant appeals from a trial court’s decision that it did not satisfy its burden of proving the existence of an arbitration agreement, the appellate court only asks whether the appellant’s evidence was (1) “uncontradicted and unimpeached” and (2) “of such a character and weight as to leave no room for a judicial determination that it was insufficient to support a finding.