feat(popup): add settings shortcut and codex create-pr skill

[taiiiyang]

Type of Changes

• ✨ New feature (feat)
• 🐛 Bug fix (fix)
• 📝 Documentation change (docs)
• 💄 UI/style change (style)
• ♻️ Code refactoring (refactor)
• ⚡ Performance improvement (perf)
• ✅ Test related (test)
• 🔧 Build or dependencies update (build)
• 🔄 CI/CD related (ci)
• 🌐 Internationalization (i18n)
• 🧠 AI model related (ai)
• 🔄 Revert a previous commit (revert)
• 📦 Other changes that do not modify src or test files (chore)

Description

• add a compact popup footer with a right-aligned settings shortcut that opens the options page
• use @tabler/icons-react for the popup settings action icon and add localized button text
• add a project-scoped Codex create-pr skill and register it in .codex/config.toml
• add a changeset for the popup settings shortcut and Codex PR workflow support

Related Issue

Closes #

How Has This Been Tested?

• Added unit tests
• Verified through manual testing
• pnpm check
• pnpm lint

Screenshots

• not included

Checklist

• I have tested these changes locally
• I have updated the documentation accordingly if necessary
• My code follows the code style of this project
• My changes do not break existing functionality
• If my code was generated by AI, I have proofread and improved it as necessary.

Additional Information

• includes a new .changeset/popup-settings-codex-pr-skill.md release note
• the Codex skill mirrors the repository's existing .claude/commands/create-pr.md workflow for PR creation