feat: add catalog create address refs changeset

[gustavogama-cll]

---

OPT-2301

[Copilot]

Pull request overview

Adds a new Catalog changeset + operation pair to create AddressRef entries in the Catalog-backed datastore, mirroring the existing “create contract metadata” patterns.

Changes:

• Introduces CreateAddressRefOp operation to merge the existing datastore into a new in-memory datastore and add provided AddressRef entries.
• Adds CreateAddressRefChangeset with precondition validation (non-empty input, datastore present, no duplicates, and no existing entries).
• Adds unit tests covering precondition validation and apply behavior (success + partial failure on duplicate add).

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
catalog/operations/create_address_ref.go	New operation to add address refs into a merged in-memory datastore and return the updated datastore.
catalog/changesets/create_address_ref.go	New changeset that validates input and executes the new operation, returning a ChangesetOutput with datastore + report.
catalog/changesets/create_address_ref_test.go	Tests for VerifyPreconditions and Apply, aligned with existing catalog changeset test patterns.

---

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