Add Tux Toolbar Buddy script

[0xTotoroX]

Summary

• add Tux Toolbar Buddy, a compact menu-trigger userscript that replaces the heavy Codex++ trigger with a Tux toolbar icon
• hide backend status/version clutter while preserving the original menu behavior
• update hide-usage-alert author metadata and homepage to the standalone project

Homepage

• https://github.com/0xTotoroX/tux-toolbar-buddy
• https://github.com/0xTotoroX/codex-hide-usage-alert

Validation

• node --check scripts/tux-toolbar-buddy.js
• jq . index.json >/dev/null
• SHA-256 in index.json matches local script files
• compared scripts/tux-toolbar-buddy.js with the homepage repo copy
• git diff --check