删除合并版README,按portal拆分8份文档(每端01-understanding+02-architecture-design) teacher-portal(shell/P2)+student-portal(remote/P3)+parent-portal(remote/P4)+admin-portal(remote/P6) AI Agent: ai07 (4 portals) Branch: docs/portals-stage1-stage2-design-ai07
删除合并版README,按portal拆分8份文档(每端01-understanding+02-architecture-design) teacher-portal(shell/P2)+student-portal(remote/P3)+parent-portal(remote/P4)+admin-portal(remote/P6) AI Agent: ai07 (4 portals) Branch: docs/portals-stage1-stage2-design-ai07