chore(release): bump version to v1.2.8

[vitormattos]

Release 1.2.8

This is a patch release from v1.2.7.

Changes since v1.2.7

• improve project positioning, documentation structure and contributor onboarding
• update npm package description, homepage and keywords for discoverability
• add structured bug report and feature request forms
• add pull request template and improve contribution guidance
• fix GitHub Pages demo deployment permissions and publishing path
• fix demo asset paths for GitHub Pages project hosting
• add and stabilize README screenshot regression checks
• improve screenshot failure reporting in CI
• add a duplicate action to the demo and corresponding test coverage
• update Vue and development/tooling dependencies

Version bump

• package.json: 1.2.7 -> 1.2.8
• package-lock.json: 1.2.7 -> 1.2.8

After this PR is merged, publishing GitHub release v1.2.8 will trigger the existing npm publication workflow.