Summary

• Add onNativeChange to Select so consumers can access the underlying ChangeEvent<HTMLSelectElement> without changing the existing onChange(value) API.
• Add a regression test covering the native event callback while keeping the existing value callback behavior covered.

Verification

• Static diff checked with GitHub compare: branch is 2 commits ahead of main, touching only Select.tsx and Select.test.tsx.
• Not run locally: the Codex command runner in this environment fails before launching /bin/zsh, so npm run lint:ui, npm run typecheck:ui, npm run test:ui, and npm run build:ui could not be executed here.

Audit Notes

• Compared Select behavior against Ant Design Select, Element Plus Select, and Radix Select docs. This patch addresses a small API ergonomics gap while preserving Nova UI's current public API.