Update site to OATS v1.1.0 specification

Refactor index.html to match the v1.1.0 paper: new Evaluation
Framework and Limitations sections, restructured Related Work with
comparative positioning table, expanded Threat Model, ORGA Scope of
Assurance and Gate Independence, per-requirement conformance
verification, and implementation-architecture comparison. Switch
license to CC BY 4.0, add DOI (Zenodo) badge in the hero, and move
the AI summary links into the sidebar. Replace v1.0.0 PDF with
v1.1.0.

Author: jaschadub