feat: Produktbilder automatisch per Barcode beim Import nachladen

[BEKO2210]

Nach dem JSON-Import werden Produkte mit Barcode aber ohne Foto automatisch im Hintergrund mit Bildern von Open Food Facts versorgt.

• importData() gibt jetzt IDs der Produkte ohne Foto zurück
• Neue loadImportedImages() Funktion lädt Bilder sequenziell nach
• Fortschrittsbalken in den Settings während des Ladevorgangs
• Übersetzungen für alle 6 Sprachen (de, en, pt, ar, it, fr)

https://claude.ai/code/session_015qtYL5oNDLJYrmH5JRAGqS

Description

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Refactoring (no functional changes)
• Performance improvement
• CI/CD changes

Related Issues

Screenshots

Before	After

Checklist

• My code follows the project's style guidelines
• I have performed a self-review of my code
• All UI text is in German with correct umlauts (or uses i18n keys)
• I have added translation keys for both de and en if new text was added
• npm run build completes without errors
• npm run test passes all tests
• npx tsc --noEmit reports no type errors
• No unused imports or variables (noUnusedLocals: true)
• Tailwind classes used (no separate CSS files)
• Lucide React icons used (no other icon libraries)

Testing

• Tested in Chrome
• Tested in Firefox/Safari
• Tested on mobile
• Tested offline functionality
• Tested dark mode
• Tested light mode