materializeWorkspace() creates directories in os.tmpdir() but
runBehavioral() never cleans them up on success or failure. If
execFileSync throws (timeout, signal, OOM), the workspace persists
in /tmp indefinitely with fixture data. The test file
run-evals-test.js uses try/finally cleanup (line 234), proving
the pattern was known but omitted in production code.
Fix: Wrap eval execution in try/finally with best-effort
fs.rmSync cleanup.
The skillName argument from --behavioral has zero validation and is
used directly in path.join() for reading .json files, reading
SKILL.md, and WRITING .grading.json results. A value like
'../../etc/passwd' traverses outside the project directory for
both reads and writes.
Fix: Validate skillName against /^[a-z0-9]+(-[a-z0-9]+)*$/ before
any filesystem operations. This matches the existing KEBAB_CASE
validation in skill-lint.js.
Sunil