Constant SYS_SILO_UNVEIL 

pub const SYS_SILO_UNVEIL: usize = 810; // 810usize

Restrict filesystem access for a silo (unveil).

• path_ptr: pointer to the path to reveal
• path_len: length of the path
• perms_ptr: pointer to the permissions string (e.g., “rwx”)
• perms_len: length of the permissions string

Only paths that have been unveiled are accessible. Once a path is unveiled, the silo cannot unveil additional paths (monotonic).