Move model catalog normalization and package-owned catalog schema/types into model-catalog-core while keeping public plugin SDK model catalog declarations on the existing SDK surface. Verified focused tests, package-boundary compile, full build, changed gate, declaration leak grep, CI, and autoreview.
Move model catalog ref helpers into @openclaw/model-catalog-core/model-catalog-refs and update internal callers/package-boundary aliases. Also fix the timestamp predicate typing that blocked prod type checks on current main.
* refactor: extract model catalog core package
* refactor: route model catalog imports through package boundary
* build: include model catalog in plugin sdk package dts
* fix: preserve static fallback model metadata
