## Why
Elevated Windows sandbox setup could turn the built-in read-only protections
for workspace metadata into deny-write paths, creating metadata directories
that did not already exist.
## What changed
- Track whether filesystem permission entries come from a built-in profile or
were explicitly configured.
- Exclude generated metadata defaults from direct Windows deny-write overrides
while continuing to enforce explicit read-only carveouts for the same paths.
- Preserve the distinction while materializing and normalizing permission
paths, without exposing generated defaults as user configuration.
## Testing
Added Windows coverage confirming that elevated sandbox setup leaves missing
workspace metadata absent and still produces overrides for explicit metadata
carveouts.
GitOrigin-RevId: 701bcb229f631b18ab5ced22f3edf6f303d932f3