feat(admin): 管理端改为多标签导航

- 菜单点击打开标签页，标签可关闭，关闭当前标签自动切换相邻标签
- 页面面板 v-show 保活，切换标签保留筛选/分页/选中状态
- 激活标签仍刷新数据，登录/退出重置标签
- 补充多标签契约测试

xiaoqu-agent-service/front/tests/source-contract.test.mjs

@@ -29,3 +29,16 @@ test('prototype interactions expose stable test ids', async () => {
     assert.match(source, new RegExp(`data-testid=["']${testId}["']`), testId)
   }
 })
+
+test('multi-tab navigation exposes tab bar and close controls', async () => {
+  const source = await readFile(new URL('../src/App.vue', import.meta.url), 'utf8')
+  assert.match(source, /data-testid=["']admin-tabbar["']/, 'admin-tabbar')
+  assert.match(source, /admin-tab-\$\{tab\.id\}/, 'admin-tab-*')
+  assert.match(source, /admin-tab-close-\$\{tab\.id\}/, 'admin-tab-close-*')
+  assert.match(source, /openTabs\.includes\('tokens'\)/, 'tokens panel gated by openTabs')
+  assert.match(source, /openTabs\.includes\('clients'\)/, 'clients panel gated by openTabs')
+  assert.match(source, /openTabs\.includes\('tools'\)/, 'tools panel gated by openTabs')
+  assert.match(source, /openTabs\.includes\('scopes'\)/, 'scopes panel gated by openTabs')
+  assert.match(source, /openTabs\.includes\('audit'\)/, 'audit panel gated by openTabs')
+  assert.match(source, /function closeTab\(/, 'closeTab handler')
+})