Add Positron to homepage hero

[gregswinehart]

Summary

Modernizes the homepage hero animation by replacing MP4 videos with Lottie JSON animations, providing better editability, smaller file sizes, and improved loop transitions.

Before

After

Changes

Animation System

• Replace MP4 video animations with Lottie JSON format for both light and dark modes
• Add graceful fade-out at end of animation loop (layers fade sequentially for smooth transition)
• Fine-tune animation properties:
• Layer 3 (foreground document): scales to 70%, positioned at x:148, fades to 65% opacity
• Staggered fade-out timing: layer 3 fades frames 1440-1490, layers 1-2 fade frames 1459-1509
• Update dark mode hero banner background color to #1C2F3D

Lottie Implementation

• Self-host lottie-web library (v5.12.2) instead of CDN for reliability and offline support
• Add Subresource Integrity (SRI) hash for security verification
• Load script once with defer attribute for optimal performance
• Wrap animation initialization in DOMContentLoaded for proper timing

File Organization

• images/hero-dark/ - Dark mode animation JSON + image assets (img_0.png, img_1.png, img_2.png)
• images/hero-light/ - Light mode animation JSON + image assets (same structure)
• js/lottie.min.js - Self-hosted animation library
• Remove old MP4 files: hero_animation.mp4, hero_animation_dark.mp4

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🤖 Generated with Claude Code

[gregswinehart]

@cscheid are you ok with bringing in lottie.min.js locally to do these animations?

[github-actions]

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