refactor: EventDetailCard 重命名为 EventCard，支持多变体模式

- 新增 EventCard.tsx 组件，支持 variant 属性（detail/compact）
  - 删除 EventDetailCard.tsx（功能已合并到 EventCard）
  - EventDetailModal 改用新的 EventCard 组件

src/views/Dashboard/components/EventDetailModal.tsx

@@ -8,7 +8,7 @@ import React from 'react';
 import { Modal, Space } from 'antd';
 import type { Dayjs } from 'dayjs';
 
-import { EventDetailCard } from './EventDetailCard';
+import { EventCard } from './EventCard';
 import { EventEmptyState } from './EventEmptyState';
 import type { InvestmentEvent } from '@/types';
 
@@ -82,9 +82,10 @@ export const EventDetailModal: React.FC<EventDetailModalProps> = ({
       ) : (
         <Space direction="vertical" size={12} style={{ width: '100%' }}>
           {events.map((event, idx) => (
-            <EventDetailCard
+            <EventCard
               key={idx}
               event={event}
+              variant="detail"
               borderColor={borderColor}
               secondaryText={secondaryText}
             />