[UI Enhancement] Add Back-to-Top Button for Better Navigation Experience

Description

Currently, the website lacks a quick navigation feature for users who scroll through long sections like menu, testimonials, and about page.
I would like to add a floating "Back to Top" button that:

• appears after scrolling down
• smoothly scrolls users back to the top
• follows the existing orange theme
• remains responsive across devices

Proposed Improvements

• Floating circular button at bottom-right corner
• Smooth scroll animation
• Hover effects and responsive styling
• Accessible button labels

Benefits

• Improves user navigation experience
• Enhances mobile usability
• Provides cleaner UX for long-page scrolling