## Why
MXC volume-root grants are nonrecursive, and filesystem deny globs were rejected before launch.
## What changed
- Expand volume-root grants to include existing immediate children, preserving read-only carveouts and denies. Children created directly under a volume root after policy construction are not granted access.
- Normalize filesystem object aliases before and after expansion so generated grants preserve tighter access restrictions.
- Skip unavailable volumes and uninspectable generated children.
- Resolve deny globs into concrete file and directory paths using the Windows sandbox resolver.
## Testing
Add regression tests for read-only children and aliases, normalized root access, uninspectable children, and deny glob expansion alongside explicit denies.
GitOrigin-RevId: 3242e9a30d16581d6fe5b7b6e39e0e0f71ca6ef4