docs: publish integration guides and documentation site

[nkavian]

Summary

• Publish the ODP documentation site with quick starts, guides, protocol explanations, SDK pages, worked examples, and a roadmap.
• Include the coding-agent integration guide, plan template, discovery links, and updated sitemap.
• Expand the protected-discovery example and clarify how Agents handle unknown branding image types in the draft.

Validation

• make -C ietf check passed.
• git diff --check passed.

Prepared with AI assistance. The existing branch content is preserved; only its branch name and commit message were changed when preparing this PR.