generate:types crashes on object-form localization.locales (json-schema-to-typescript TypeError: endsWith of undefined)

Describe the Bug

payload generate:types crashes with a TypeError inside json-schema-to-typescript when config-level localization.locales uses the object form ({ label, value }) and at least one collection has a localized field. The documented string-array form works fine in the identical config.

Link to the Code that Reproduces this Issue

Minimal config that crashes:

import { buildConfig } from "payload";

export default buildConfig({
  localization: {
    locales: [
      { label: "English", value: "en" },
      { label: "French", value: "fr" },
    ],
    defaultLocale: "en",
    fallback: true,
  },
  collections: [
    {
      slug: "posts",
      fields: [{ name: "title", type: "text", localized: true }],
    },
  ],
});

Swapping locales to ["en", "fr"] makes generate:types succeed — everything else unchanged.

Reproduction Steps

1. pnpm dlx create-payload-app@latest (or any Payload 3.88.0 project).
2. Set localization.locales to the object form above and add one localized field.
3. Run pnpm payload generate:types.

Expected / Actual Behaviors

Expected: types are generated for either documented locale form.
Actual: with the object form:

Error generating types: TypeError: Cannot read properties of undefined (reading 'endsWith')
    ... json-schema-to-typescript ...

Environment Info

Output of npx payload info:

Binaries:
  Node: 22.22.2
  npm: 10.9.2
  Yarn: N/A
  pnpm: 10.x
Relevant Packages:
  payload: 3.88.0
  next: 16.3.1
  @payloadcms/ui: 3.88.0
  react: 19.x
  typescript: 5.7.3
  json-schema-to-typescript: 15.0.3 (payload dependency)
Operating System: macOS 15.7

Start by reproducing the failure with the documented object-form localization.locales and a localized field, then trace the generate:types entry point into its localized-field schema generation. Check how json-schema-to-typescript receives the locale data. Done means generation succeeds for both the object and string-array locale forms, with the existing configuration unchanged.