A step's error is regularly a provider payload or a stack, and a hover
tooltip could only ever clip it: there was no way to read past the first
few lines, let alone paste it into a bug report.
The badge now teases the failure - "Error executing" plus its first
line, clamped - and opens the whole text in a dialog where it keeps its
own line breaks, scrolls, stays selectable, and copies in one click.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
