[gcomneno]

Summary

Adds a Demo-runtime-only public page explaining how Atelier-Kit consumes GiadaWare UI.

The page:

• is publicly readable only in ATELIER_STUDIO_MODE=demo;
• remains unavailable in ordinary Visitor, Local Studio, Hosted Studio and invalid/conflicting runtimes;
• adds a Demo-only navigation and sitemap entry;
• demonstrates SocialIcon, FormStatus and RelationshipGraph;
• keeps routes, domain conversion, localization and workflow state owned by Atelier-Kit;
• introduces no Studio or mutation authority;
• links to the GiadaWare UI repository, interface guide and living consumer demo documentation.

Verification

• focused GiadaWare UI public-page tests: 5/5;
• svelte-check: 0 errors, 0 warnings;
• full suite: 959/959;
• content validation: PASS;
• production build: PASS;
• git diff --check: PASS;
• manual visual review: approved.