feat(security): 优化权限控制并添加用户删除功能

- 更新 SecurityConfig，增加精确控制的公开阅读端点
- 实现用户删除功能，仅允许删除当前登录用户
- 优化用户删除接口，增加安全性检查

biji-houdaun/src/main/java/com/test/bijihoudaun/controller/UserController.java

@@ -62,14 +62,19 @@ public class UserController {
         return R.success(tokenMap);
     }
 
-    @Operation(summary = "用户删除")
-    @Parameters({
-            @Parameter(name = "id", description = "用户id",required = true)
-    })
+    @Operation(summary = "删除当前登录的用户")
     @DeleteMapping("/deleteUser")
-    public R<String> deleteUser(Integer id){
-        userService.deleteUser(id);
-        return R.success("删除成功");
+    public R<String> deleteUser(){
+        UserDetails userDetails = (UserDetails) SecurityContextHolder.getContext().getAuthentication().getPrincipal();
+        String username = userDetails.getUsername();
+        User user = userService.getOne(new com.baomidou.mybatisplus.core.conditions.query.QueryWrapper<User>().eq("username", username));
+
+        if (user == null) {
+            return R.fail("无法获取用户信息，删除失败");
+        }
+
+        userService.deleteUser(user.getId().intValue());
+        return R.success("用户删除成功");
     }
 
     @Operation(summary = "验证Token有效性")