Clearer wording when a command nests shells too deeply

A shell is the program that runs your terminal commands. Before Claude Code runs a command, it checks whether the command is safe to approve. Some commands hand shell code to another shell, which can hand it to yet another one. When a command does this too many times, Claude Code gives a reason for not approving it. That reason now reads "it hands shell code to a shell too many layers deep". It used to say "it hands shell code to a shell more times over than this reading follows".