Backend Translations with Flask-Babel

This project uses Flask-Babel for internationalization (i18n) of backend API messages.

Setup

Install Flask-Babel (already in requirements.txt):
```
pip install Flask-Babel
```
Translation files are located in: app/translations/

Mark strings for translation in your code:

from flask_babel import _

return jsonify({"error": _("Error message")})

Extract translatable strings:

pybabel extract -F babel.cfg -k _ -o messages.pot app/

Update translation files:

pybabel update -i messages.pot -d app/translations

Edit translation files:
- Edit app/translations/en/LC_MESSAGES/messages.po for English
- Edit app/translations/de/LC_MESSAGES/messages.po for German
- Fill in the msgstr "" fields with translations
Compile translations:
```
pybabel compile -d app/translations
```

Use Python string formatting with named parameters:

_("Error occurred: %(error)s", error=str(e))

In the .po file:

msgid "Error occurred: %(error)s"
msgstr "Fehler aufgetreten: %(error)s"

The backend automatically selects the language based on the Accept-Language HTTP header sent by the frontend. Supported languages:

Use the provided script to set up translations. Run from the backend/ directory:

./scripts/setup_translations.sh

Or from the project root:

./backend/scripts/setup_translations.sh