Add future plan for ACE architecture refactoring to support:
- ACE name and description fields for better management
- Multiple paths and resource pools in a single ACE entry
- Solving ACE explosion problem (N groups × M pools)
- Updated permission checking logic for the new structure
Updated the roadmap document to reflect the implemented three-step
permission check logic in the feature/simple-user-isolation branch.
Added comprehensive design memory documenting:
- Core problem and design conflicts
- Three-step permission check implementation
- Key design decisions and advantages
- Use cases and scenarios
- Design evolution process
