feat: add Ressourcen timeline view with group ordering (alpha.14)

- New timeline page showing all groups and active events in parallel
- Group order API endpoints with persistence (GET/POST /api/groups/order)
- Customizable group ordering with visual controls
- Fix CSS and TypeScript lint errors
- Update documentation and bump version to 2026.1.0-alpha.14

server/init_defaults.py

@@ -68,6 +68,7 @@ with engine.connect() as conn:
             ('holiday_banner_enabled', 'true', 'Ferienstatus-Banner auf Dashboard anzeigen'),
             ('organization_name', '', 'Name der Organisation (wird im Header angezeigt)'),
             ('refresh_seconds', '0', 'Scheduler Republish-Intervall (Sekunden; 0 deaktiviert)'),
+            ('group_order', '[]', 'Benutzerdefinierte Reihenfolge der Raumgruppen (JSON-Array mit Group-IDs)'),
         ]
     
         for key, value, description in default_settings:

server/routes/groups.py

@@ -208,3 +208,55 @@ def get_groups_with_clients():
         })
     session.close()
     return jsonify(result)
+
+
+@groups_bp.route("/order", methods=["GET"])
+def get_group_order():
+    """Retrieve the saved group order from system settings."""
+    from models.models import SystemSetting
+    session = Session()
+    try:
+        setting = session.query(SystemSetting).filter_by(key='group_order').first()
+        if setting and setting.value:
+            import json
+            order = json.loads(setting.value)
+            return jsonify({"order": order})
+        return jsonify({"order": None})
+    except Exception as e:
+        print(f"Error loading group order: {e}")
+        return jsonify({"order": None})
+    finally:
+        session.close()
+
+
+@groups_bp.route("/order", methods=["POST"])
+@require_role('admin')
+def save_group_order():
+    """Save the custom group order to system settings."""
+    from models.models import SystemSetting
+    session = Session()
+    try:
+        data = request.get_json()
+        order = data.get('order')
+        
+        if not order or not isinstance(order, list):
+            return jsonify({"success": False, "error": "Invalid order data"}), 400
+        
+        import json
+        order_json = json.dumps(order)
+        
+        setting = session.query(SystemSetting).filter_by(key='group_order').first()
+        if setting:
+            setting.value = order_json
+        else:
+            setting = SystemSetting(key='group_order', value=order_json)
+            session.add(setting)
+        
+        session.commit()
+        return jsonify({"success": True})
+    except Exception as e:
+        session.rollback()
+        print(f"Error saving group order: {e}")
+        return jsonify({"success": False, "error": str(e)}), 500
+    finally:
+        session.close()