molluskandClaude Opus 4.8
6541834e0d
Add two boundary assertions to format_duration_renders_mss_and_hmmss: 59s -> "0:59" (last second of m:ss form) and 3599s -> "59:59" (final second before the output switches to h:mm:ss at 3600). Gemini-authored (junior), senior-reviewed against the real diff and independently re-verified (cargo test --lib + clippy clean). First task driven through the headless `agy --print --sandbox` loop. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>