feat: ignore generated demo directories and remove tracked demo files

- Add gitignore patterns for CLI-generated demo directories (*-demo/, *-enhanced/, etc.)
- Remove previously tracked demo files that are now auto-generated
- Demo sites will be auto-created on-demand by CLI during just demo commands

.gitignore

@@ -97,6 +97,13 @@ test-output/
 client-dist/
 output/
 
+# Generated demo sites (auto-generated by CLI)
+test-sites/**/*-demo/
+test-sites/**/*-enhanced/
+test-sites/**/*-auto/
+test-sites/**/*-temp/
+test-sites/**/*-full/
+
 # Air temporary files
 tmp/
 .air/