Core.Shell

Core.Shell defines product- and framework-neutral shell semantics. It owns stable owner-scoped IDs, audience profiles and capabilities, versioned navigation catalogs, validation, compatibility diagnostics, visibility evaluation seams, and platform target resolution seams.

It deliberately does not contain URLs, routes, image URLs, cookie names, storage keys, product names, product catalogs, authorization rules, workflows, or product defaults. Products own catalogs and policy. Core.Portal.Chrome, Core.Maui, and Core.Avalonia map the contract to their platform.

schemaVersion is the Core-owned document format. catalogVersion is the product-owned catalog revision. Schema 3 is current, schema 2 is compatible, and schema 1 is accepted with a deprecation diagnostic. Unknown future versions are rejected instead of guessed.