task-2(壳层/路由): 冻结 /admin-vue/ base 与 History 路由契约为单一事实源

新增 src/config/app.ts（APP_BASE_PATH/ensureAppBasePath/joinAdminPath），
vite.config base、router createWebHistory、AdminLayout logo 路径统一消费常量，
禁止散落字面量；8 用例覆盖归一化/幂等/空段/单段/非法输入与字面量单源。

admin-frontend-vue/tests/admin-scaffold.test.ts

@@ -0,0 +1,31 @@
+import assert from 'node:assert/strict'
+import test from 'node:test'
+import { existsSync, readFileSync } from 'node:fs'
+import { resolve } from 'node:path'
+
+test('admin build uses the standalone /admin-vue base path from single source', () => {
+  const config = readFileSync(resolve('vite.config.ts'), 'utf8')
+  const appConfig = readFileSync(resolve('src/config/app.ts'), 'utf8')
+  assert.match(appConfig, /export const APP_BASE_PATH = '\/admin-vue\/'/)
+  assert.match(config, /base:\s*APP_BASE_PATH/)
+  assert.match(config, /outDir:\s*['"]dist['"]/)
+})
+
+test('admin entry and first batch pages exist', () => {
+  for (const file of [
+    'index.html',
+    'src/main.ts',
+    'src/layout/AdminLayout.vue',
+    'src/pages/account/UsersPage.vue',
+    'src/pages/account/MenusPage.vue',
+    'src/pages/account/GroupsPage.vue',
+  ]) {
+    assert.equal(existsSync(resolve(file)), true, `${file} should exist`)
+  }
+})
+
+test('admin frontend does not depend on the client new_web_source', () => {
+  const packageJson = readFileSync(resolve('package.json'), 'utf8')
+  assert.doesNotMatch(packageJson, /new_web_source/)
+})
+