feat: add demo site configuration flag

- Introduce `DemoSiteEnabled` variable in operation settings
- Provide a configurable flag to enable/disable demo site functionality

web/src/components/OperationSetting.js

@@ -58,6 +58,7 @@ const OperationSetting = () => {
     DefaultCollapseSidebar: false, // 默认折叠侧边栏
     RetryTimes: 0,
     Chats: "[]",
+    DemoSiteEnabled: false,
   });
 
   let [loading, setLoading] = useState(false);

web/src/pages/Setting/Operation/SettingsGeneral.js

@@ -21,6 +21,7 @@ export default function GeneralSettings(props) {
     DisplayInCurrencyEnabled: false,
     DisplayTokenStatEnabled: false,
     DefaultCollapseSidebar: false,
+    DemoSiteEnabled: false,
   });
   const refForm = useRef();
   const [inputsRow, setInputsRow] = useState(inputs);
@@ -188,6 +189,23 @@ export default function GeneralSettings(props) {
                 />
               </Col>
             </Row>
+            <Row>
+              <Col span={8}>
+                <Form.Switch
+                  field={'DemoSiteEnabled'}
+                  label={t('演示站点模式')}
+                  size='default'
+                  checkedText='｜'
+                  uncheckedText='〇'
+                  onChange={(value) =>
+                    setInputs({
+                      ...inputs,
+                      DemoSiteEnabled: value
+                    })
+                  }
+                />
+              </Col>
+            </Row>
             <Row>
               <Button size='default' onClick={onSubmit}>
                 {t('保存通用设置')}