[backnotprop]

Summary

• bump only @plannotator/ui to 0.35.1
• replace the published workspace:* core dependency with exact @plannotator/core@0.25.0 while preserving Bun workspace linking
• add a CI package smoke that verifies the source and Bun-packed manifests, every exported tarball target, generated assets, and a transitive install in an external pnpm consumer
• correct the UI publishing documentation and mark 0.35.0 unsuitable for external consumption

Verification

• bun install --frozen-lockfile
• bun run typecheck
• bun run --cwd packages/ui typecheck
• bunx tsc --noEmit -p packages/ui/tsconfig.strict-consumer.json
• bun run --cwd packages/ui smoke:package
• DOM_TESTS=1 bun test --isolate packages/ui/components/AnnotationToolstrip.test.tsx
• git diff --check

The package smoke uses exact-pinned pnpm@10.34.3 in an OS-temp consumer outside this monorepo and does not add @plannotator/core directly, so the dependency must resolve transitively from the packed UI manifest.

This PR does not publish or merge the package.