Update documentation to reflect current project structure

- Rename CLAUDE.MD to CLAUDE.md for correct case-sensitive formatting
- Update file structure diagrams across all documentation files
- Document standard Astro src/ directory structure (layouts, pages)
- Add 404.astro custom error page to documentation
- Include robots.txt and sitemap integration in docs
- Update current status to reflect completed features:
  - Custom 404 page with themed styling
  - Sitemap integration for SEO
  - Accessibility improvements (ARIA labels, semantic HTML)
- Update code examples to use proper import paths from src/
- Mark completed TODO items (404 page, sitemap, accessibility)

All documentation now accurately reflects the standard Astro project
structure with layouts in src/layouts/ and pages in src/pages/.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

PROJECT_CONTEXT.md

@@ -29,6 +29,10 @@ The site currently has:
 - ✅ Support section
 - ✅ Docker deployment setup
 - ✅ Responsive design
+- ✅ Custom 404 page with themed styling
+- ✅ Sitemap integration for SEO
+- ✅ robots.txt for search engines
+- ✅ Accessibility improvements (ARIA labels, semantic HTML)
 
 ## What Might Be Added Later
 
@@ -55,9 +59,9 @@ Main content is in `src/pages/index.astro`. Each section is wrapped in semantic
 
 ### File Organization
 - `src/layouts/` - Reusable layouts (currently just BaseLayout)
-- `src/pages/` - Routes (index.astro = homepage)
+- `src/pages/` - Routes (index.astro = homepage, 404.astro = error page)
 - `src/components/` - Reusable components (empty, ready for future use)
-- `public/` - Static assets (favicon, images)
+- `public/` - Static assets (favicon.svg, robots.txt)
 
 ## Communication Style