Sable Sands UI Pro Pack

Included in this pack:
- premium Bootstrap 5 design system in assets/css/app.css
- upgraded shared shell (header/sidebar/mobile menu)
- login page visual redesign
- fixed login placeholder binding bug in login.php
- redesigned dashboard
- redesigned reservation list
- redesigned availability planner

How to apply:
1. Back up your current files.
2. Upload and overwrite the matching files/folders.
3. Clear browser cache with Ctrl+F5.
4. Test login, dashboard, reservation list, reservation form, and planner.

Important:
- This pack assumes assets are served from /assets/... and pages from /modules/...
- If your installation folder is not web root, we can do a base_url pass next.
