Bundle includes 500KB+ of unused Zod locales

[brainkim]

Description

When @b9g/zen is bundled, it pulls in ~598KB of Zod locale files (50+ languages) that are never used.

@b9g/zen                                     598.4 KB     79  14.4%

The 79 files are almost entirely Zod locales:

// node_modules/@b9g/zen/node_modules/zod/v4/locales/ar.js
// node_modules/@b9g/zen/node_modules/zod/v4/locales/az.js
// node_modules/@b9g/zen/node_modules/zod/v4/locales/be.js
// ... (50+ locale files)

Root Cause

This is a known Zod issue where export * as locales from "../locales/index.js" prevents tree-shaking:

• Zod Mini - Tree shaking not removing locales colinhacks/zod#5561

The issue affects esbuild, webpack, and turbopack. There's currently no workaround except using Rollup.

Suggested Workarounds

Until Zod fixes this upstream:

1. Wait for Zod to fix the tree-shaking issue
2. Consider using zod/mini if it has better tree-shaking characteristics
3. Consider a lighter validation library for simple use cases

Impact

For applications that don't use @b9g/zen database features, this adds ~600KB of unused code to the bundle.