[performance] Bundle size vs. Radix

## Reproducible example

1. Go to https://ui.shadcn.com/create
2. Export with Radix and Base UI
3. Use the new Next.js bundle size analyzer https://nextjs.org/docs/app/guides/package-bundling#nextjs-bundle-analyzer-experimental to compare both

## Current behavior

You will get:

Base UI 463.57 KB

Radix 443.64 KB

So Base UI is 20KB minified larger, while it benefits from utils deduplication relative to Radix since Radix imports Base UI Combobox. So we likely have a 30KB minified bloat problem. gzipped usualy /3 the size, so a +10KB gzipped issue.

## Expected behavior

Base UI is smaller.

## Base UI version

v1.0.0

## Additional context

Solving this would help convince people to migrate. I noticed this trying to compare the two https://www.notion.so/mui-org/2026-Shadcn-Radix-vs-Base-UI-demo-2dfcbfe7b6608090b851c5f6e1f60e95.