v0.3.5 - Latest move marker

What's changed

• Added a visual marker for the latest played stone.
• Exposed the latest move to assistive technology with aria-current=step and localized cell labels.
• Fixed the empty recent-match state so it follows the selected interface language.
• Added focused regression coverage for localization and latest-move labeling.

Verification

• Node syntax checks passed for src/engine.js and src/main.js.
• Node test suite passed: 17 tests.
• git diff --check passed.
• GitHub Actions CI and Pages deployment passed.

Note: interactive browser smoke testing was not run because the Codex in-app browser is currently blocked from accessing both localhost and the GitHub Pages domain by enterprise network policy.