v0.4.0

Added

• Apache License 2.0 (LICENSE), declared as Apache-2.0 in
  plugin.json and marketplace.json, with a License badge in the
  README.
• A documentation site (MkDocs Material, Diátaxis-structured) under
  docs/, deployed to GitHub Pages via .github/workflows/pages.yml,
  covering tutorials, how-to guides, reference, and explanation for the
  whole plugin — especially the assessment.
• CHANGELOG.md and a changelog-driven release workflow: every version
  bump publishes a GitHub Release whose notes are the matching CHANGELOG
  section.
• CI for the TDAB structural suite, a PR-time changelog gate, and
  required status checks (A-tier structural assertions, Changelog gate) on a protected main.
• AGENTS.md, ONBOARDING.md, and REFLECTION_LOG.md for contributors,
  plus a "Dual-surface sync" harness constraint (command ≡ skill) and
  synced Cursor / Copilot / Windsurf convention files.
• README prerequisites and status / scope badges; repo description,
  topics, and homepage.

Changed

• The Sovereign Engineer call-to-action now points to the AI-readiness
  campaign URL (https://leanpub.com/thesovereignengineer/c/ai-readiness)
  — in the assessment's reading-path CTA (command + skill) and the
  "buy the book" CTAs in the README and the docs.