fix(schedules): support editable schedule notes

apps/admin/src/pages/Schedules/index.tsx

@@ -947,6 +947,19 @@ const SchedulesPage: React.FC = () => {
               />
             </Form.Item>
 
+            <Form.Item
+              name="notes"
+              label="备注"
+              rules={[{ max: 500, message: '备注不能超过500字' }]}
+            >
+              <Input.TextArea
+                rows={3}
+                maxLength={500}
+                showCount
+                placeholder="可填写排课说明、设备需求或临时调整原因"
+              />
+            </Form.Item>
+
             <Form.Item
               name="timeRange"
               label="上课时段"