v0.12.0

Added

• Published to npm as @radicool/throughline.
  The multi-agent installer is now installable everywhere: npx @radicool/throughline init.
  (The unscoped throughline npm name belongs to an unrelated package.)
• Tag-driven release automation. Pushing a vX.Y.Z tag now runs the full CI
  validation, publishes to npm with provenance via trusted publishing, and creates
  a GitHub Release with notes extracted from this changelog
  (.github/workflows/release.yml + ci/extract-changelog.mjs).

Changed

• Install command for Cursor/Codex/AGENTS.md targets is now npx @radicool/throughline init
  (previously documented as npx throughline init, which was never published).
• README version badge now reads live from the npm registry.