Why: Core PR #26 added the node id/source fields to ts/types.ts (the
single authority); the mirror is regenerated so the sync header and
content match make contracts output exactly (manual edits drift).
Evidence: File generated by the make contracts copy steps; combined
verification in the Dev workspace after re-pinning.
Impact: Header banner plus the already-reviewed id/source fields.
Refs: Core PR #26; Dev task feature/generative-ui-u2