docs: apply All Tuner Labs corporate MkDocs style

[davidpoblador]

Summary

• Add All Tuner Labs logo and custom CSS (wine/burgundy brand colors with light/dark mode)
• Replace deep purple/amber palette with custom brand colors via media-query palette
• Add full theme features (navigation tracking/tabs/expand/top, search suggest/highlight, code annotate)
• Add complete markdown extensions set (mermaid, inline highlight, snippets, tables, TOC with permalink)
• Add site metadata (author, edit_uri), social links, and plugins

Test plan

• Run mkdocs serve locally and verify the site renders with corporate branding
• Verify light/dark mode toggle works
• Verify logo appears in header

🤖 Generated with Claude Code

[claude]

Code review

No issues found. Checked for bugs and CLAUDE.md compliance.