fix: 统一项目版本号并修复Maven Central发布配置

- 将父项目版本从2.0.5升级到2.0.6
- 移除子项目中的硬编码版本号，改为继承父项目版本
- 将内部依赖引用改为使用${project.version}变量
- 添加RELEASE-2.0.6.md发布说明文档

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

jhinno-openapi-sdk-spring-boot-starter/pom.xml

@@ -5,7 +5,6 @@
     <modelVersion>4.0.0</modelVersion>
 
     <artifactId>jhinno-openapi-sdk-spring-boot-starter</artifactId>
-    <version>2.0.6</version>
     <packaging>jar</packaging>
     <name>Jhinno OpenAPI SDK for Java SpringBoot Starter</name>
     <description>The Jhinno OpenAPI SDK for Java used for accessing Jhinno OpenApi Service</description>
@@ -14,14 +13,14 @@
     <parent>
         <groupId>com.jhinno</groupId>
         <artifactId>jhinno-openapi-java-sdk-parent</artifactId>
-        <version>2.0.5</version>
+        <version>2.0.6</version>
     </parent>
 
     <dependencies>
         <dependency>
             <groupId>com.jhinno</groupId>
             <artifactId>jhinno-openapi-java-sdk</artifactId>
-            <version>2.0.6</version>
+            <version>${project.version}</version>
         </dependency>
 
         <dependency>