refactor(config): Switch to environment variables for API keys

- Modifies docker-compose.yml to use  for injecting the Gemini API key, which is more robust than volume mounting.
- Updates helpers.py to prioritize reading the API key from the  environment variable.
- Removes the now-redundant file-based key loading logic from config.py and the Dockerfile.
- This change completely bypasses the problematic file system interactions within the container, providing a definitive fix for the 'API Key missing' error.

config.py

@@ -482,30 +482,9 @@ class Config:
         "NetCologne"
     ]
 
-    # --- API Schlüssel Speicherung (werden in main() geladen) ---
+    # --- API Schlüssel Speicherung (werden jetzt via Env Var geladen) ---
     API_KEYS = {}
 
-    @classmethod
-    def load_api_keys(cls):
-        """Laedt API-Schluessel aus den definierten Dateien."""
-        logger = logging.getLogger(__name__)
-        logger.info("Lade API-Schluessel...")
-        print(f"DEBUG: Attempting to load API keys. BASE_DIR: {BASE_DIR}") # Debug print
-        cls.API_KEYS['openai'] = cls._load_key_from_file(API_KEY_FILE)
-        cls.API_KEYS['serpapi'] = cls._load_key_from_file(SERP_API_KEY_FILE)
-        cls.API_KEYS['genderize'] = cls._load_key_from_file(GENDERIZE_API_KEY_FILE)
-
-        if cls.API_KEYS.get('openai'):
-            openai.api_key = cls.API_KEYS['openai']
-            logger.info("OpenAI API Key erfolgreich geladen.")
-        else:
-            logger.warning("OpenAI API Key konnte nicht geladen werden. OpenAI-Funktionen sind deaktiviert.")
-
-        if not cls.API_KEYS.get('serpapi'):
-             logger.warning("SerpAPI Key konnte nicht geladen werden. Suchfunktionen sind deaktiviert.")
-        if not cls.API_KEYS.get('genderize'):
-             logger.warning("Genderize API Key konnte nicht geladen werden. Geschlechtserkennung ist eingeschraenkt.")
-
     @staticmethod
     def _load_key_from_file(filepath):
         """Hilfsfunktion zum Laden eines Schluessels aus einer Datei."""