docs: 记录工作台任务优先验收（portal-task-first-redesign）

.trellis/spec/hyb-oa/frontend-react-vite-design.md

@@ -327,6 +327,9 @@ before doing work.
 - Focused Playwright coverage for changed workbench or profile routes.
 - Screenshot evidence for first-login welcome, workbench first screen and
   profile default view when changing these surfaces.
+- Workbench baseline screenshots must explicitly clear onboarding localStorage
+  such as `hyb_oa_show_welcome` and `hyb_oa_onboarding_active` before capture,
+  unless the test is intentionally verifying the welcome dialog.
 
 ## Convention: Detail And Mobile Command Surfaces