合并页面恢复钱包刷新

将可见性与焦点事件合并到同一零延迟刷新任务，避免前台切换产生连续请求。

卸载时清理待执行定时器，并补充双事件回归测试。

src/components/platform-entry/PlatformEntryActiveFlowShell.test.tsx

@@ -267,7 +267,7 @@ describe('PlatformEntryActiveFlowShell', () => {
     await screen.findByLabelText('泥点 67');
   });
 
-  it('refreshes the shared wallet when the authenticated page regains focus', async () => {
+  it('coalesces visibility and focus refreshes when the page returns to the foreground', async () => {
     authUiMock.value.user = {
       id: 'user-1',
       publicUserCode: '100001',
@@ -300,6 +300,7 @@ describe('PlatformEntryActiveFlowShell', () => {
     await screen.findByLabelText('泥点 10');
 
     await act(async () => {
+      document.dispatchEvent(new Event('visibilitychange'));
       window.dispatchEvent(new Event('focus'));
     });