🔒 Add password protection feature to hubs with authentication flow

📝 Update custom slug help text to remove ID suffix explanation

💄 Update example URL in hub form help text

✨ Add custom slug support for hub URLs with validation and UI

🔧 Tweak db config

🎨 Add empty state component with improved visual design for hub links

⬆️ Upgrade Ruby setup action to v1.241.0 and artifact upload to v4.6.2