feat: 事件详情页 URL ID 加密，防止用户遍历

- 新增 idEncoder.ts 工具：使用 Base64 + 前缀混淆加密 ID
- 路由改为查询参数形式：/event-detail?id=xxx
- 更新所有入口使用 getEventDetailUrl() 生成加密链接
- 兼容旧链接：纯数字 ID 仍可正常访问

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

src/views/Dashboard/Center.js

@@ -62,6 +62,7 @@ import {
 } from 'react-icons/fi';
 import MyFutureEvents from './components/MyFutureEvents';
 import InvestmentPlanningCenter from './components/InvestmentPlanningCenter';
+import { getEventDetailUrl } from '@/utils/idEncoder';
 
 export default function CenterDashboard() {
   const { user } = useAuth();
@@ -441,7 +442,7 @@ export default function CenterDashboard() {
                         <VStack align="stretch" spacing={3}>
                           <LinkOverlay
                             as={Link}
-                            to={`/event-detail/${event.id}`}
+                            to={getEventDetailUrl(event.id)}
                           >
                             <Text fontWeight="medium" fontSize="md" noOfLines={2}>
                               {event.title}