优化：完善广告收益顶部筛选默认值 (#78)

## 本次改动

- 类型和场景筛选增加明确的“全部”选项
- 将默认每页记录数从 1000 调整为 50

## 范围

仅修改 `src/app/(main)/ad-revenue-report/page.tsx`。

---------

Co-authored-by: linkeyu <798648091@qq.com>
Reviewed-on: #78
Co-authored-by: linkeyu <linkeyu@wonderable.ai>
Co-committed-by: linkeyu <linkeyu@wonderable.ai>

src/app/(main)/ad-revenue-report/page.tsx

@@ -43,6 +43,8 @@ import type {
 import UserAdRevenueDrawer from './UserAdRevenueDrawer';
 
 const { RangePicker } = DatePicker;
+const DEFAULT_PAGE_SIZE = 50;
+const ALL_FILTER_VALUE = '__all__';
 
 // 广告类型标签
 const TYPE_TAG: Record<string, { color: string; label: string }> = {
@@ -396,13 +398,13 @@ export default function AdRevenueReportPage() {
   const [scene, setScene] = useState<string | undefined>();
   const [granularity, setGranularity] = useState<'day' | 'hour'>('day');
   const [sortBy, setSortBy] = useState<'time' | 'ecpm'>('time'); // 明细排序:time=时间倒序 / ecpm=eCPM 倒序
-  const [limit, setLimit] = useState<number>(1000); // 默认拉满接口单页上限，供单次流程广告数分位统计
+  const [limit, setLimit] = useState<number>(DEFAULT_PAGE_SIZE);
   const [page, setPage] = useState<number>(1); // 当前页码(后端分页;1 起)
   const [queriedGranularity, setQueriedGranularity] = useState<'day' | 'hour'>('day'); // 本次结果对应的粒度,决定是否显示「小时」列
   const [queriedMultiDay, setQueriedMultiDay] = useState(false); // 本次结果是否跨多天,决定显示「日期」列 + 按天/按小时图
   const [data, setData] = useState<AdRevenueReport | null>(null);
   const [allFlowItems, setAllFlowItems] = useState<AdRevenueRow[]>([]);
-  const [queriedLimit, setQueriedLimit] = useState<number>(1000);
+  const [queriedLimit, setQueriedLimit] = useState<number>(DEFAULT_PAGE_SIZE);
   const [loading, setLoading] = useState(false);
   const [formulaOpen, setFormulaOpen] = useState(false);
   // 点用户手机号弹出的「用户广告收益详情」半屏抽屉(userId + 手机号;null=关闭)
@@ -784,12 +786,11 @@ export default function AdRevenueReportPage() {
           <Space size={6}>
             <Typography.Text type="secondary">类型</Typography.Text>
             <Select
-              placeholder="全部"
-              value={adType}
-              onChange={setAdType}
-              allowClear
+              value={adType ?? ALL_FILTER_VALUE}
+              onChange={(value) => setAdType(value === ALL_FILTER_VALUE ? undefined : value)}
               style={{ width: 150 }}
               options={[
+                { value: ALL_FILTER_VALUE, label: '全部' },
                 { value: 'reward_video', label: '看视频' },
                 { value: 'draw', label: 'Draw 信息流' },
                 { value: 'withdrawal_video', label: '提现看视频' },
@@ -799,12 +800,11 @@ export default function AdRevenueReportPage() {
           <Space size={6}>
             <Typography.Text type="secondary">场景</Typography.Text>
             <Select
-              placeholder="全部"
-              value={scene}
-              onChange={setScene}
-              allowClear
+              value={scene ?? ALL_FILTER_VALUE}
+              onChange={(value) => setScene(value === ALL_FILTER_VALUE ? undefined : value)}
               style={{ width: 130 }}
               options={[
+                { value: ALL_FILTER_VALUE, label: '全部' },
                 { value: 'comparison', label: '比价' },
                 { value: 'coupon', label: '领券' },
                 { value: 'welfare', label: '福利' },