📚 Improved documentation and log files for better system understanding & maintenance. 🖥️🔍

backend/app.py

@@ -1851,8 +1851,13 @@ def admin_page():
             'success_rate': success_rate
         }
         
-        # Tab-Parameter
+        # Tab-Parameter mit erweiterten Optionen
         active_tab = request.args.get('tab', 'users')
+        valid_tabs = ['users', 'printers', 'jobs', 'system', 'logs']
+        
+        # Validierung des Tab-Parameters
+        if active_tab not in valid_tabs:
+            active_tab = 'users'
         
         # Benutzer laden (für users tab)
         users = []
@@ -7225,12 +7230,6 @@ if __name__ == "__main__":
         # Cleanup bei Fehler
         if shutdown_manager:
             shutdown_manager.force_shutdown(1)
-        else:
-            try:
-                stop_queue_manager()
-            except:
-                pass
-            sys.exit(1)
         else:
             try:
                 stop_queue_manager()