Add Impressum and QR code management templates

- Created a new Impressum page with legal information and contact details.
- Developed admin link page for linking QR codes to events with form functionality.
- Implemented QR code dashboard for managing QR code sets, including creation and quick actions.
- Added detailed view for QR code sets, allowing addition of QR codes and management actions.
- Introduced static file serving for favicon and related images.
- Established views for static content pages (about, contact, privacy, terms).
- Implemented translation management scripts for compiling and updating translations.

app/i18n/__init__.py

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+import gettext
+import os
+from typing import Dict, List, Callable, Any
+from fastapi import Request, Depends
+from babel.support import Translations
+from functools import lru_cache
+from gettext import gettext as _  # Ensure `_` is imported for translations
+
+# Define supported languages
+SUPPORTED_LANGUAGES = {
+    'en': 'English',
+    'de': 'Deutsch',
+}
+
+DEFAULT_LANGUAGE = 'de'  # Default is German
+
+# Path to translations
+LOCALE_DIR = os.path.join(os.path.dirname(__file__), 'locales')
+
+@lru_cache(maxsize=None)
+def get_translation(lang_code: str) -> gettext.NullTranslations:
+    """
+    Load and cache translations for the given language
+    """
+    translations = gettext.translation(
+        'messages', 
+        localedir=LOCALE_DIR, 
+        languages=[lang_code], 
+        fallback=True
+    )
+    return translations
+
+def get_locale_from_request(request: Request) -> str:
+    """
+    Determine the best language based on:
+    1. URL parameter (e.g., '?lang=de')
+    2. User session
+    3. Accept-Language header
+    4. Default language
+    """
+    # Check URL parameter
+    lang_param = request.query_params.get('lang')
+    if lang_param in SUPPORTED_LANGUAGES:
+        return lang_param
+        
+    # Check session
+    session = request.session.get('language')
+    if session in SUPPORTED_LANGUAGES:
+        return session
+    
+    # Check Accept-Language header
+    accept_language = request.headers.get('accept-language', '')
+    if accept_language:
+        for lang in accept_language.split(','):
+            lang_code = lang.split(';')[0].strip().lower()
+            lang_code = lang_code.split('-')[0]  # Convert 'en-US' to 'en'
+            if lang_code in SUPPORTED_LANGUAGES:
+                return lang_code
+    
+    return DEFAULT_LANGUAGE
+
+def get_translator(locale: str = Depends(get_locale_from_request)):
+    """
+    Return a FastAPI dependency that provides the translation function
+    """
+    translations = get_translation(locale)
+    gettext_func = translations.gettext
+    
+    # Make the gettext function available with both _ and gettext names
+    return {
+        "_": gettext_func,
+        "gettext": gettext_func,
+        "locale": locale
+    }