feat: 添加分类提案功能，包括提案表单和相关后端逻辑

backend/src/main/java/com/openisle/controller/PostController.java

@@ -73,7 +73,12 @@ public class PostController {
       req.getStartTime(),
       req.getEndTime(),
       req.getOptions(),
-      req.getMultiple()
+      req.getMultiple(),
+      req.getProposedName(),
+      req.getProposedSlug(),
+      req.getProposalDescription(),
+      req.getApproveThreshold(),
+      req.getQuorum()
     );
     draftService.deleteDraft(auth.getName());
     PostDetailDto dto = postMapper.toDetailDto(post, auth.getName());