feat(cost): 添加成本管理业务pom

- 创建 ruoyi-cost 模块作为成本管理业务模块
- 配置模块继承自 ruoyi 父项目
- 添加核心框架依赖 ruoyi-framework
- 集成 lombok 注解处理器支持
- 引入 swagger 注解用于 API 文档生成
- 配置 JUnit 和 Spring Boot 测试依赖
- 设置模块打包方式为 jar 格式

ruoyi-cost/pom.xml

@@ -0,0 +1,55 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <parent>
+        <artifactId>ruoyi</artifactId>
+        <groupId>com.ruoyi</groupId>
+        <version>3.8.9</version>
+    </parent>
+    <modelVersion>4.0.0</modelVersion>
+    <packaging>jar</packaging>
+    <artifactId>ruoyi-cost</artifactId>
+
+    <description>成本管理业务模块</description>
+
+    <dependencies>
+        <!-- 核心框架 -->
+        <dependency>
+            <groupId>com.ruoyi</groupId>
+            <artifactId>ruoyi-framework</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <scope>provided</scope>
+        </dependency>
+
+        <!-- Swagger 注解 -->
+        <dependency>
+            <groupId>io.swagger</groupId>
+            <artifactId>swagger-annotations</artifactId>
+            <version>1.6.2</version>
+        </dependency>
+
+        <!-- JUnit 测试 -->
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter</artifactId>
+            <scope>test</scope>
+        </dependency>
+        
+        <!-- Spring Boot Test -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+</project>