test: guest onboarding, logged-in isolation, optional real_name

Add guest-onboarding and logged-in-and-isolation specs; remove moicen-unionid-chain;
MOICEN_E2E_EXPECTED_REAL_NAME for 欢迎回来+姓名; CI secret; workers=1; longer goto timeouts.

Made-with: Cursor

playwright.config.ts

@@ -7,6 +7,7 @@ loadEnv({ path: path.join(__dirname, '.env.e2e') });
 export default defineConfig({
   testDir: './tests',
   timeout: 120_000,
+  workers: 1,
   expect: { timeout: 30_000 },
   use: {
     baseURL: