Archived Admin App Spec

This file originally described the older client-specific apps/admin surface.

It is retained only as an archive marker after the starter kit normalized around:

• apps/app
• apps/marketing
• apps/docs

Current source-of-truth starter docs live in:

• docs/app/apps/product-app-spec.md
• docs/app/apps/marketing-app-spec.md
• docs/app/foundation/architecture.md
• docs/app/archive/README.md