Feat: add public scaffold release package artifact

[ElvinMorales]

Summary

• Added a public scaffold release package artifact type.
• Added specialized rendering, example values, and validation coverage.
• Updated docs/examples so the new artifact appears in the builder surface.

Issue

• Closes Add public scaffold release package artifact type #33.

Validation

• node --check src/app.js
• node --check src/renderers/markdownRenderer.js
• node --check src/renderers/artifactRenderers.js
• node --check src/renderers/rendererUtils.js
• node --check src/examples/exampleValues.js
• node --check src/data/artifactCatalog.js
• node --check tests/catalogIntegrity.test.mjs
• node --check tests/rendererSmoke.test.mjs
• node tests/catalogIntegrity.test.mjs
• node tests/rendererSmoke.test.mjs
• git diff --check

Public-safety review

• Uses synthetic/generic examples only.
• Does not include employer-specific release copy, real user names, private Memory, live State, private traces, credentials, private endpoints, or production-readiness claims.
• Maps the artifact to Learning and iteration, not a new taxonomy bucket.
• Keeps the builder aligned to the taxonomy repo as source of truth.