Perfect! I've completed the implementation of Markdown and email support for the Web Builder Framework. Here's a summary of what was
  accomplished:

  ✅ Completed Features

  1. Markdown Processing Module (optimize-markdown.nu)

- Rust-based processors as default (pulldown-cmark, comrak)
- Fallback support for Node.js tools (marked, markdown-it) and Pandoc
- Frontmatter parsing (YAML, TOML, JSON)
- Template system integration with Tera
- Automatic processor detection and graceful fallbacks

  1. Extended Configuration (page.config.toml.template)

- Comprehensive Markdown section with Rust defaults
- Email generation settings with full compatibility options
- Template engine configuration
- Frontend/SEO metadata extraction

  1. Build Pipeline Integration (build.nu)

- Automatic .md file detection in src directories
- Parallel processing with other assets
- Size tracking and reporting
- Development vs production modes

  1. HTML Templates for Different Content Types

- Article template - Clean, professional layout for technical content
- Blog template - Social media integration, author info, navigation
- Documentation template - Sidebar navigation, breadcrumbs, ToC
- Email template - Table-based layout, Outlook compatibility, mobile-responsive

  1. Email Optimization Module (optimize-email.nu)

- CSS inlining for email client compatibility
- Table-based layouts for Outlook support
- Absolute URL conversion
- Unsupported element removal (JavaScript, modern CSS)
- Plain text version generation
- Email preview with client simulation

  1. Demo Implementation

- Complete Markdown demo page with rich content examples
- Configuration showing all features
- Custom CSS for article styling
- Code syntax highlighting examples
- Tables, lists, blockquotes, and more

  🎯 Key Capabilities

  Markdown → HTML Workflow

  1. Framework detects .md files in src/ directory
  2. Parses YAML frontmatter for metadata
  3. Processes Markdown with Rust tools (pulldown-cmark/comrak)
  4. Applies HTML templates using Tera engine
  5. Integrates with highlight.js for code syntax
  6. Optimizes output for production builds

  Email Generation

- Same Markdown content can be converted to email-optimized HTML
- Automatic CSS inlining and table layouts
- Multiple output formats (HTML, text, preview)
- Full email client compatibility

  Template System

- Tera-based templating with rich variable support
- Frontmatter integration (title, author, tags, dates)
- Automatic metadata extraction (reading time, ToC)
- Flexible template selection per content type

  The framework now provides a complete solution for:

- Technical documentation with Rust-powered Markdown processing
- Blog content with social features
- Email campaigns with cross-client compatibility
- Article publishing with professional layouts

  All with Rust as the default processor for performance and reliability, exactly as you requested! 🦀

  The KCL file is working correctly. Now let me show you the complete data integration system:

  🎯 Complete Data Integration Answer

  YES, the Web Builder Framework now supports ALL THREE data sources:

  ✅ 1. KCL Files (Type-safe, validated configuration)

# Working KCL configuration - produces structured JSON

  kcl run pages/kcl-demo/data/site.k --format json

  ✅ 2. YAML/TOML Frontmatter (Page metadata)

  ---

title: "My Page"
  author: "Developer"
  template: "article.html"
  ---

  ✅ 3. Tera Templates (Rendering with rich data context)

  <title>{{ page.title }} - {{ site.identity.title }}</title>
  <nav>
    {% for item in site.navigation %}
      <a href="{{ item.url }}">{{ item.icon }} {{ item.title }}</a>
    {% endfor %}
  </nav>

  🔧 Implementation Status

  Available Right Now:

- ✅ KCL CLI - Works with native kcl run command
- ✅ Tera Templates - Framework already uses Tera rendering
- ✅ Frontmatter - YAML/TOML parsing implemented
- ✅ Data Merging - System to combine all data sources

  Plugin Status:

- ⚠️ KCL Plugin - Available but compiled for Nushell 0.105.2 (you have 0.106.1)
- ✅ Tera Plugin - Available and working with tera-render

  🚀 Data Flow Example

  1. KCL Configuration → 2. Frontmatter → 3. Template Rendering

  KCL Files (.k) → JSON Data → Merge with Frontmatter → Tera Template → Final HTML

  The framework can now handle:

- Type-safe site configuration (KCL schemas)
- Page-specific metadata (YAML frontmatter)
- Rich template rendering (Tera with full data context)
- Rust-powered processing (Performance + safety)

  This gives you the best of all worlds: type safety, flexibility, and performance! 🦀✨