chore(main): release 0.2.2 (#4)

refactor: move UCP schemas under schemas/ucp/ parent directory

docs: rewrite README to give ACP equal coverage

chore(main): release 0.2.1 (#3)

refactor: remove unnecessary wrappers and dual string/atom handling

fix: normalize Message.parse return type and tighten retry error matching

refactor: remove validate_openai_product_feed/1 convenience function

refactor: version ACP schemas and make return_policy conditionally required

refactor: replace JSON Schema with Ecto embedded schema for product feed

feat: add OpenAI product feed schema to validator

chore: exclude mix tasks from hex package

chore(main): release 0.2.0 (#2)

fix(ci): chain hex-publish in release-please workflow

feat!: upgrade to UCP spec 2026-01-23

docs: add product schema comparison table to protocols guide