style(班级 PK): 「AI 分析」按钮和旁边的「这周 / 这学期」一样高

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

apps/web/src/oj/class/pk.vue

@@ -156,7 +156,6 @@ async function analyze() {
         </div>
         <n-button
           v-if="teacher && isDesktop"
-          size="small"
           secondary
           type="info"
           :disabled="selected.length < 2"