Feature: Implement Multi-language Support (i18n) for Notifuse

[ShokoCosplayPro]

[Feature] Implement Multi-language Support (i18n) for Notifuse

📝 Description

The goal is to integrate an internationalization (i18n) system to allow Notifuse to support multiple languages. Currently, text strings are hardcoded, which limits the accessibility of the tool for global users.

🛠 Technical Specifications

1. File Structure

Translations must be managed via local JSON files stored in a /locales directory:

• locales/locale.en.json (Source of truth / Reference)
• locales/locale.fr.json
• locales/locale.es.json
• (Additional languages to be added easily later)

2. Core Logic

• Default Language: English (en) must be the default locale.
• Fallback Mechanism: If a specific translation key is missing in the selected language (e.g., fr), the system must automatically fall back to the English (en) version to prevent empty UI elements or errors.
• Configuration: The active language should be configurable via a global configuration file or an environment variable.