fix(app): navigate tabs by selection history

[Hona]

Summary

• rename desktop menu navigation to Previous Tab and Next Tab
• traverse tab selection history instead of visual tab order
• skip closed tabs and duplicate entries for the active tab

Testing

• bun test --preload ./happydom.ts ./src/desktop-menu.test.ts ./src/context/tab-history.test.ts ./src/context/tabs.test.ts
• bun typecheck
• pre-push workspace typecheck

[Copilot]

Copilot was unable to review this pull request because the user who requested the review has reached their quota limit.

[brian-dlee]

⚠️ Blocking Beta Release

This PR cannot be merged into the beta branch due to: Fetch failed

Please resolve this issue to include this PR in the next beta release.