MissingFromCatalog

When this happens

• ✓ Instance is in a Catalog version group
• ✓ One catalog (or zero — implicit "default") exists in the project
• ✘ Instance's dependency is not defined in any catalog
• ✘ Instance does not use the catalog: protocol
• ! Fix: add dependency to the catalog and replace specifier with catalog:

The specifier added to the catalog is the unique value when all instances are identical, or the highest semver when all instances are semver.