Clean up codebase: remove unused demos and test files

- Remove dan-eden-portfolio and devigo-web demo sites
- Clean up demo testing infrastructure and scripts
- Remove frontend test files (html-preservation, style-detection tests)
- Update configuration and auth improvements
- Simplify demo structure to focus on core functionality

This cleanup reduces repository size and focuses on essential demos.

insertr.yaml

@@ -26,20 +26,6 @@ server:
       discovery:
         enabled: false    # Uses explicit class="insertr" markings
         aggressive: false
-    - site_id: "dan-eden-portfolio"
-      path: "./demos/dan-eden-portfolio_enhanced"
-      source_path: "./demos/dan-eden-portfolio"
-      auto_enhance: true
-      discovery:
-        enabled: true     # Auto-discover elements (no explicit markings)
-        aggressive: false
-    - site_id: "devigo-web"
-      path: "./demos/devigo-web_enhanced"
-      source_path: "./demos/devigo-web"
-      auto_enhance: true
-      discovery:
-        enabled: false    # Uses explicit class="insertr" markings
-        aggressive: false
     # Example additional site configuration:
     # - site_id: "mysite"
     #   path: "/var/www/mysite"
@@ -73,4 +59,4 @@ library:
   use_cdn: false                       # Use CDN in production
   cdn_base_url: "https://cdn.jsdelivr.net/npm/@insertr/lib"
   minified: false                      # Use full version for debugging
-  version: "1.0.0"                     # Library version
+  version: "1.0.0"                     # Library version