More shell commands using $$ now ask for permission

Before running a shell command, Claude Code reads it to decide whether it is safe to run without asking. Its reader now treats $ as a special variable name when checking subscripts. As a result, commands with patterns such as $$[ or $$:x are judged too complex to read and lead to a permission prompt.

The message shown when the reader cannot follow a ${ ...; } command substitution is also shorter. A command substitution runs a command and uses its output in place.