feat(app): add internationalization (i18n) support

[BenjaminOddou]

💬 Description

This PR introduces internationalization (i18n) support to the Nuxt Studio editor, allowing the UI to be translated.

It provides a mechanism for users to add their own translations or override the defaults.

💡 Implementation Details

This PR implements a solution by "injecting" the translations at runtime:

1. Module (src/module/src/module.ts):

   • Gathers all translations using defu to merge defaults (src/app/locales), user-defined locales (app/locales/studio), app.config options and nuxt.config options.
   • Creates a Vite virtual module (virtual:studio-i18n-messages) to provide this merged JSON.
   • Adds a new Nuxt plugin (studio-i18n-plugin.client.mjs).

2. Nuxt Plugin (studio-i18n-plugin.client.mjs):

   • This plugin can import from virtual:studio-i18n-messages because it runs within the Nuxt project's context.
   • It attaches the resolved messages to window.__NUXT_STUDIO_I18N_MESSAGES__.

3. Studio App (src/app):

   • src/app/src/i18n.ts is refactored into a factory function (createStudioI18n) that accepts a messages object.
   • src/app/src/main.ts, during configureApp, now reads the messages from window.__NUXT_STUDIO_I18N_MESSAGES__ and passes them to createStudioI18n to dynamically create the i18n instance.

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Project	Deployment	Preview	Comments	Updated (UTC)
content-studio	Ready	Preview	Comment	Nov 13, 2025 7:15pm

[BenjaminOddou]

in playground/docus/nuxt.config.ts you can add

export default defineNuxtConfig({
  studio: {
    i18n: {
      defaultLocale: 'fr',
    },
  },
})

the result

[pkg-pr-new]

npm i https://pkg.pr.new/nuxt-content/studio/nuxt-studio@70

commit: 143f720

[larbish]

Hello @BenjaminOddou, thanks a lot for your PR 🙏 I'm finishing a massive refactor (#91) and I'll then resolve conflicts with your branch to merge it!

[BenjaminOddou]

@larbish, great news ! Don't hesitate to ping me if there is anything I can do. 😄

[larbish]

Here is what I've updated:

• Extract i18n logic into separate i18n.ts file for better code organization
• Removed vite module, it's enough to use addTemplate directly since it's loaded by a plugin
• Relocate locale files to module/src/locales/ to ensures locale files are bundled with the module at build time (imports from app/src/locales/ wouldn't work in production)
• Replaced globby with node native
• Fixed defaultLocale handling it was not override

@farnabaz @atinux Can you see another way instead of window for cross boundary communication between module and app? I'm not a fan of it

[atinux]

I like using window as shared objects between the website & web elements

[atinux]

Amazing! Au top :)

[farnabaz]

Generally looks good to me 👍 Great work

Using window to share data between web-component and host is quite alright IMO. However I'm not fan of having translations inside module and passing them to Vue app.

UI and Translations are App's responsibility.

[larbish]

We've decided with @farnabaz to remove the translations override and simplify the PR:

• no need of plugin (using runtime config and host to share default locale)
• move locales in app and fetch it at runtime (set locale and load messages at runtime)

@farnabaz Feel free to merge once you've checked option types with build version