feat: add GitHub Pages deployment workflow

[fx]

Summary

• Add GitHub Actions workflow to automatically build and deploy to GitHub Pages
• Create production build configuration for minified output
• Add landing page with installation instructions
• Update documentation with GitHub Pages deployment options

Details

This PR sets up automatic deployment to GitHub Pages whenever changes are pushed to the main branch. Users will be able to use the hosted version at https://fx.github.io/liebe/panel.js without needing to build or host the panel themselves.

Changes Made:

1. GitHub Actions Workflow (.github/workflows/deploy.yml):

   • Builds the Home Assistant panel in production mode
   • Creates GitHub Pages artifacts
   • Deploys to GitHub Pages with proper permissions

2. Production Build Config (vite.config.ha.prod.ts):

   • Minified output for smaller file size
   • Production mode settings
   • Source maps disabled

3. Landing Page (.github/pages-index.html):

   • Simple installation instructions
   • Links to repository and panel.js

4. Documentation Updates:

   • Updated README.md with GitHub Pages installation option
   • Added deployment section to CLAUDE.md
   • New npm script for production builds

Testing

• All tests pass locally (npm test)
• Linting passes (npm run lint)
• TypeScript checks pass (npm run typecheck)
• Production build works (npm run build:ha:prod)
• Workflow will be tested when merged to main

Deployment Notes

After merging, the workflow will:

1. Automatically run on pushes to main
2. Build and deploy to https://fx.github.io/liebe/
3. Make the panel available at https://fx.github.io/liebe/panel.js

Users can then simply add this URL to their Home Assistant configuration without needing to build or host anything themselves.