Revert "First pass at pulling the v1.5 CLI, TUI, and Launcher clients into v2."

This reverts commit 467b01edd6.

clients/cli/src/error-handler.ts

@@ -1,20 +0,0 @@
-function formatError(error: unknown): string {
-  let message: string;
-
-  if (error instanceof Error) {
-    message = error.message;
-  } else if (typeof error === "string") {
-    message = error;
-  } else {
-    message = "Unknown error";
-  }
-
-  return message;
-}
-
-export function handleError(error: unknown): never {
-  const errorMessage = formatError(error);
-  console.error(errorMessage);
-
-  process.exit(1);
-}