Release 0.9.5 markdown share actions

[ehud-am]

Summary

• Add rendered Markdown print/share/export actions and visible refresh control
• Add editor undo/redo plus panel-scoped Select All forwarding from the native app
• Reopen the last used folder on startup with platform Documents fallback
• Bump release metadata to 0.9.5

Validation

• npm run verify
• npm pack --dry-run
• packaging/macos/release/package-app.sh
• packaging/macos/release/test-package.sh