Add i18n support to Svelte language chooser using typesafe-i18n

[Copilot]

The language-chooser-svelte-daisyui app lacked internationalization support. This adds translations for English, Spanish, and French using typesafe-i18n, matching the locales available in the React app.

Changes

• Added typesafe-i18n (5.26.2) with Svelte adapter configuration
• Translation dictionaries for en, es, fr in src/i18n/ with all UI strings
• Locale initialization in main.ts with browser language detection via navigatorDetector
• Language switcher dropdown in App.svelte header
• Component updates to use $LL translation store in App.svelte, LanguageChooser.svelte, CustomizationModal.svelte

Usage

<script lang="ts">
  import LL from "./i18n/i18n-svelte";
  import { setLocale } from "./i18n/i18n-svelte";
</script>

<h1>{$LL.app.title()}</h1>
<button onclick={() => setLocale("es")}>Español</button>

The locale is reactive - changing it updates all translated strings across components.

Screenshots

English

Spanish

French

Modal (French)

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Add translations to Svelte app</issue_title>
<issue_description>On the ui-controller branch, the language-chooser-svelte-daisyui app needs to support multiple languages.

Use the typesafe-i18n package to support multiple interface languages for the Svelte app.

The Svelte app should use the same locales that language-chooser-react-mui does. These locales are located under the locales folder. Currently, we support English, Spanish (es-419), and some French. The Svelte app should support each of these languages.

To demonstrate that the translations are working, add a dropdown in App.svelte that changes the interface language.

The target branch for these changes is ui-controller.</issue_description>

<agent_instructions>To run the Svelte app, use nx dev @ethnolib/language-chooser-svelte-daisyui from the command line.</agent_instructions>

Comments on the Issue (you are @copilot in this section)

• Fixes Add translations to Svelte app #5

---

✨ Let Copilot coding agent set things up for you — coding agent works faster and does higher quality work when set up for your repo.