feat: add smooth scroll animations to features page

[AbhiVarde]

Feature

Enhanced features page with smooth, grouped scroll animations for better visual engagement.

Solution

• Implemented Intersection Observer API for scroll-based animations
• Added grouped animations per feature section (Analytics, Insights, Privacy, Cloud)
• Applied staggered fade-in effect with 30ms delay between feature cards
• Used subtle translateY (15px) for smooth upward motion
• Set fast 0.3s transition duration for snappy, professional feel
• Maintained all original Umami components and design system

Technical Details

• Created FeatureSection component with animation logic
• Each section triggers animation independently when entering viewport
• Animation parameters: opacity 0→1, translateY 15px→0, 0.3s ease-out
• Threshold: 0.05 with -80px bottom margin for optimal trigger timing

Testing

Verified smooth animations and proper stagger timing across different viewport sizes and scroll speeds.

Changes

• Updated app/(website)/features/page.tsx with animated FeatureSection component
• Preserved all existing feature content and Umami design components
• No breaking changes to existing functionality