feat: 成就摘要最近解锁从 5 个放宽到 10 个

个人主页删掉徽章卡片后腾出空间，多展示几个。

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

achievement/views/oj.py

@@ -61,7 +61,7 @@ class AchievementSummaryAPI(APIView):
         total = sum(total_by_rarity.values())
         unlocked = sum(unlocked_by_rarity.values())
 
-        recent = list(UserAchievement.objects.filter(user=user, achievement__visible=True).select_related("achievement").order_by("-unlock_time")[:5])
+        recent = list(UserAchievement.objects.filter(user=user, achievement__visible=True).select_related("achievement").order_by("-unlock_time")[:10])
 
         return self.success(
             {