chore: bump version to v2026.4.290 and fix commits list styling}
- Bump build version from v2026.4.286 to v2026.4.290 across all docs and markdown files
- Bump package.json version from 2026.4.287 to 2026.4.291
- Add list-group-flush class to commits list in commits-list.twig for cleaner card styling