Security
- Preserve literal pipe characters inside argv arguments. Pipeline syntax is now recognized only from a discrete
|argv element. - Prevent attached pipe arguments from creating unintended pipeline stages or bypassing command-specific argument policies such as the
awkexternal-access check. - Attached pipes are no longer implicit pipeline syntax. Use
["cmd1", "|", "cmd2"].
Fixes GHSA-q8pm-q3r2-q7cg and GHSA-7wg7-jj87-qp4c.