style: ruff format 全仓库

行宽 180 下把历史遗留的折行表达式合并，无语义改动。

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

comment/models.py

@@ -43,5 +43,3 @@ class Comment(models.Model):
         indexes = [
             models.Index(fields=["problem", "create_time"], name="comment_problem_time_idx"),
         ]
-
-