Fix demo site auto-enhancement and content persistence

- Restructure demo directory from test-sites/ to demos/ with flattened layout
- Add auto-enhancement on server startup for all sites with auto_enhance: true
- Fix inconsistent content ID generation that prevented dan-eden-portfolio content persistence
- Update server configuration to enhance from source to separate output directories
- Remove manual enhancement from justfile in favor of automatic server enhancement
- Clean up legacy test files and unused restore command
- Update build system to use CDN endpoint instead of file copying

demos/README.md

@@ -0,0 +1,40 @@
+# Test Sites Collection
+
+This directory contains a collection of real-world websites for testing insertr CMS functionality across different site types, CSS frameworks, and complexity levels.
+
+## Directory Structure
+
+- **`simple/`** - Simple sites with vanilla CSS and minimal layouts
+- **`framework-based/`** - Sites using CSS frameworks (Bootstrap, Tailwind, etc.)
+- **`complex/`** - Complex layouts with advanced interactions
+- **`templates/`** - Template files for new test sites
+- **`scripts/`** - Automation utilities for downloading and enhancing sites
+- **`results/`** - Testing results, reports, and documentation
+
+## Site Categories
+
+### Simple Sites
+- **dan-eden-portfolio** - Clean personal portfolio with minimal styling
+- **github-pages-simple** - Basic GitHub Pages site with standard layout
+
+### Framework-Based Sites
+- **bootstrap-docs** - Bootstrap documentation sections
+- **tailwind-landing** - Tailwind CSS marketing pages
+
+### Complex Sites
+- **stripe-product** - Enterprise product pages with rich content
+- **linear-features** - Modern SaaS feature pages
+
+## Testing Process
+
+1. **Download** - Use scripts to fetch HTML and assets
+2. **Enhance** - Add insertr classes to content sections
+3. **Test** - Verify functionality across different layouts
+4. **Document** - Record results and compatibility notes
+
+## Each Site Includes
+
+- Original HTML files
+- `assets/` directory with CSS, JS, and images
+- `README.md` with site-specific testing notes
+- `insertr-config.json` with enhancement configuration