feat(bugcollect): 新增 PUT /issues/{id}/reopen 接口

- LogService.reopenIssue() 将状态设回 open
- LogController 暴露 /issues/{id}/reopen 端点

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

xuqm-bugcollect-service/src/main/java/com/xuqm/bugcollect/controller/LogController.java

@@ -106,6 +106,12 @@ public class LogController {
         return ApiResponse.ok();
     }
 
+    @PutMapping("/issues/{id}/reopen")
+    public ApiResponse<Void> reopenIssue(@PathVariable Long id) {
+        logService.reopenIssue(id);
+        return ApiResponse.ok();
+    }
+
     @PutMapping("/issues/{id}/assign")
     public ApiResponse<Void> assignIssue(
             @PathVariable Long id,

xuqm-bugcollect-service/src/main/java/com/xuqm/bugcollect/service/LogService.java

@@ -270,6 +270,14 @@ public class LogService {
         issueRepository.save(issue);
     }
 
+    @Transactional
+    public void reopenIssue(Long id) {
+        LogIssueEntity issue = issueRepository.findById(id)
+                .orElseThrow(() -> new IllegalArgumentException("Issue not found: " + id));
+        issue.setStatus("open");
+        issueRepository.save(issue);
+    }
+
     @Transactional
     public void assignIssue(Long id, String assignee) {
         issueRepository.updateAssignee(id, assignee);