docs: strengthen AEO discovery and validation

[aronchick]

Summary

• upgrade Docusaurus and React, standardize CI on npm, remove the redundant Yarn lockfile, and add Dependabot coverage
• add four evidence-led compute-over-data, architecture, edge-orchestration, and data-locality guides with page-specific JSON-LD
• generate llms-full and segmented LLM corpus files; add sitemap lastmod and build-artifact validation

Validation

• npm run typecheck
• npm run spell-check
• npm run build
• npm run validate:site
• npm audit --audit-level=low
• actionlint .github/workflows/*.yml

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