feat(API): 修改文章ID类型为String并添加CORS配置

将文章ID从Integer类型改为String类型以支持更灵活的ID格式
添加CORS配置类解决跨域问题，允许所有来源访问API

src/main/java/com/qf/myafterprojecy/service/IArticleService.java

@@ -7,7 +7,7 @@ import com.qf.myafterprojecy.pojo.dto.ArticleDto;
 import java.util.List;
 
 public interface IArticleService {
-    ResponseMessage<Article> getArticleById(Integer id);
+    ResponseMessage<Article> getArticleById(String id);
     ResponseMessage<List<Article>> getAllArticles();
     ResponseMessage<Article> saveArticle(ArticleDto articleDto);
     ResponseMessage<Article> updateArticle(Integer id, ArticleDto articleDto);