docs: update changelogs

CHANGELOG.md

@@ -5,6 +5,15 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [v1.6.19](https://github.com/nocobase/nocobase/compare/v1.6.18...v1.6.19) - 2025-04-14
+
+### 🐛 Bug Fixes
+
+- **[client]**
+  - Fix the issue of preview images being obscured ([#6651](https://github.com/nocobase/nocobase/pull/6651)) by @zhangzhonghe
+
+  - In the form block, the default value of the field configuration will first be displayed as the original variable string and then disappear ([#6649](https://github.com/nocobase/nocobase/pull/6649)) by @zhangzhonghe
+
 ## [v1.6.18](https://github.com/nocobase/nocobase/compare/v1.6.17...v1.6.18) - 2025-04-11
 
 ### 🚀 Improvements

CHANGELOG.zh-CN.md

@@ -5,6 +5,15 @@
 格式基于 [Keep a Changelog](https://keepachangelog.com/zh-CN/1.0.0/),
 并且本项目遵循 [语义化版本](https://semver.org/spec/v2.0.0.html)。
 
+## [v1.6.19](https://github.com/nocobase/nocobase/compare/v1.6.18...v1.6.19) - 2025-04-14
+
+### 🐛 修复
+
+- **[client]**
+  - 修复预览图片被遮挡的问题 ([#6651](https://github.com/nocobase/nocobase/pull/6651)) by @zhangzhonghe
+
+  - 表单区块中，字段配置的默认值会先显示为原始变量字符串然后再消失 ([#6649](https://github.com/nocobase/nocobase/pull/6649)) by @zhangzhonghe
+
 ## [v1.6.18](https://github.com/nocobase/nocobase/compare/v1.6.17...v1.6.18) - 2025-04-11
 
 ### 🚀 优化