Add GitHub Pages landing page with architecture detection

[sunnypatneedi]

Summary

Adds a professional GitHub Pages landing page with automatic architecture detection to help users download the correct build (Apple Silicon vs Intel).

Features

• Auto-detection: Detects Mac architecture and recommends correct download
• Dark mode: Respects prefers-color-scheme
• Responsive design: Mobile-first, works on all screen sizes
• Auto-updates: GitHub Actions workflow updates version on each release
• Fallbacks: Works without JavaScript, handles non-Mac users
• Performance: 32KB CSS, 4.4KB JS, expected Lighthouse 95+

Implementation

• Static HTML landing page with hero, features, how-it-works, system requirements, FAQ
• JavaScript architecture detection (Apple Silicon vs Intel)
• Tailwind CSS 4.x with brand colors and dark mode
• GitHub Actions workflow auto-updates version on release publish
• Assets: app icon and settings screenshot

Deployment

After merge, enable GitHub Pages:

1. Repository Settings → Pages
2. Source: Deploy from a branch
3. Branch: main, Folder: /docs
4. Save

Landing page will be live at: https://familiar-software.github.io/familiar/

Test plan

• Tested locally in browser
• Architecture detection works correctly
• Dark mode toggles properly
• Responsive on mobile/tablet/desktop
• Download links format correctly
• All sections render properly

🤖 Generated with Claude Code

[talsraviv]

Nice! Intentionally holding off a pretty landing page but this is such a good idea for when we do that, i didn't know github pages could do all that!

[talsraviv]

@Hyaxia what do you think? maybe we just go with this!

[Hyaxia]

@talsraviv would definitely consider this option for the landing page when we get to it! thank you @sunnypatneedi!
im leaving the PR open for now