🎉 Feature: Added new database files for improved performance and stability in backend/database directory.

backend/app.py

@@ -597,6 +597,7 @@ def log_response_info(response):
 def check_session_activity():
     """Prüft Session-Aktivität und meldet inaktive Benutzer ab"""
     if current_user.is_authenticated:
+        from utils.utilities_collection import SESSION_LIFETIME
         last_activity = session.get('last_activity')
         if last_activity:
             try:
@@ -846,6 +847,7 @@ def api_get_printer_status():
 def api_session_status():
     """API-Endpunkt für Session-Status"""
     try:
+        from utils.utilities_collection import SESSION_LIFETIME
         last_activity = session.get('last_activity')
         if last_activity:
             last_activity_time = datetime.fromisoformat(last_activity)
@@ -877,6 +879,7 @@ def api_session_status():
 def api_session_heartbeat():
     """API-Endpunkt für Session-Heartbeat"""
     try:
+        from utils.utilities_collection import SESSION_LIFETIME
         # Session-Aktivität aktualisieren
         session['last_activity'] = datetime.now().isoformat()
         session.permanent = True
@@ -898,6 +901,7 @@ def api_session_heartbeat():
 def api_session_extend():
     """API-Endpunkt für Session-Verlängerung"""
     try:
+        from utils.utilities_collection import SESSION_LIFETIME
         data = request.get_json() or {}
         extend_minutes = data.get('extend_minutes', 30)