Codex round 1 (P3): the valid cases were only 1, 10 and 20 digits long,
so `if (2..10).contains(&raw.len()) { return None }` survived all four
tests while rejecting every serial a freshly started daemon hands out.
Verified: that mutant passes the old suite and fails the new test.
Also corrects the doc comment — leading zeroes are accepted (harmless
and unambiguous), only whitespace padding is rejected.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
molluskandClaude Opus 4.8
87de5213fe