Support RO-Crate 1.3

[fbacall]

https://www.researchobject.org/ro-crate/blog/2026-06-23/announcing-ro-crate-1-3

Simply updates the default spec version

[Copilot]

Pull request overview

Updates the library’s default RO-Crate spec version to 1.3 and adds fixture crates/tests intended to verify reading crates across spec versions (including older versions).

Changes:

• Bump ROCrate::Metadata::DEFAULT_VERSION to 1.3 and add 1.3 to SUPPORTED_VERSIONS.
• Update documentation/tests to reflect 1.3 as the default spec.
• Add new 1.2 and 1.3 fixture crates plus reader tests for them.

Reviewed changes

Copilot reviewed 10 out of 10 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
lib/ro_crate/model/metadata.rb	Sets RO-Crate 1.3 as the default declared spec version and marks it supported.
test/crate_test.rb	Updates expectations for the default metadata version/context/spec URL to 1.3.
test/reader_test.rb	Adds reader tests for 1.2/1.3 fixtures (currently needs fixes to actually use those fixtures and assert correct preview source).
README.md	Updates README to state conformance with RO-Crate 1.3 and links to the 1.3 spec.
test/fixtures/crate-spec1.2/*	Adds a 1.2 RO-Crate fixture for reader compatibility testing.
test/fixtures/crate-spec1.3/*	Adds a 1.3 RO-Crate fixture for reader compatibility testing.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.