feat(抽奖): 活动删除按钮 + 格子数可选(8/9,默认8)

- 活动列表加"删除"(ConfirmButton→DELETE /activities/:id)
- activity-form 格子数选项 [8,9]，新建默认 8（原来写死只有 9）
- service: deleteLotteryActivity；i18n 删除文案

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

packages/ui/src/services/admin/lottery.ts

@@ -391,3 +391,20 @@ export async function getLotteryDrawList(
     }
   );
 }
+
+/**
+ * 删除抽奖活动（软删；运行中需先暂停）
+ * DELETE /v1/admin/lottery/activities/:id
+ */
+export async function deleteLotteryActivity(
+  body: { id: number },
+  options?: { [key: string]: any }
+) {
+  return request<API.Response & { data?: any }>(
+    `${import.meta.env.VITE_API_PREFIX || ""}/v1/admin/lottery/activities/${body.id}`,
+    {
+      method: "DELETE",
+      ...(options || {}),
+    }
+  );
+}