[FEATURE]: Add catalog semantics metadata for roles, names, state, and interactions

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## Is your feature request related to a problem? Please describe.

Catalog schemas describe wire shape but not framework-neutral semantic role, accessible-name source, structural child slots, state/value bindings, or supported interactions. Renderers know this behavior in code; accessibility, testing, inspection, and policy tools otherwise hard-code component names or infer arbitrary property names.

## Describe the Proposed Solution

Define optional versioned declarative catalog metadata for semantic role, accessible-name source/normalization, structural slots, value/data-path and enabled/selected/checked/validation sources, and supported interactions with their binding/action property. Include it in catalog version/digest inputs. It must contain no executable callbacks, and tooling should fail closed when required metadata is absent.

## Describe Alternatives Considered

Component-name inference fails for custom catalogs. Inspecting Flutter widgets or a DOM is renderer-specific. Private registries fragment semantics and drift from the advertised catalog.

## Additional Context

#2197 covers action intent and #1528 covers schema-driven child resolution; both are complementary to this broader catalog-owned semantics contract.

Der Issue schlägt vor, deklarative Metadaten zu Katalogschemata hinzuzufügen. Beginne damit, die vorhandenen Definitionen der Katalogschemata und die zugehörigen Issues #2197 und #1528 zu lesen. Verstehe die Konzepte semantischer Rollen, der Quellen für zugängliche Namen, struktureller Slots und Zustandsbindungen. Ermittle, wo Katalogmetadaten derzeit in der Codebasis verarbeitet werden und wie sie ohne ausführbare Callbacks erweitert werden können.

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