test: 添加全面的单元测试和集成测试

- 添加 common 模块单元测试 (ObjectHelper, SnowflakeHelper)
- 添加 database 模块集成测试 (SimpleServiceSupport, @SoftDelete)
- 添加 Controller REST API 契约测试
- 配置 H2 数据库和 p6spy 用于测试
- 更新 openspec 配置，添加并行任务和提问工具规则

spring-boot-service-template-common/pom.xml

@@ -11,6 +11,14 @@
 
   <artifactId>spring-boot-service-template-common</artifactId>
 
+  <dependencies>
+    <dependency>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-starter-test</artifactId>
+      <scope>test</scope>
+    </dependency>
+  </dependencies>
+
   <build>
     <plugins>
       <plugin>