Add missing mount flags (local, protect)

[kerlenton]

Summary

Add support for local and protect mount flags on Darwin.

Motivation

While comparing mount command output with gopsutil results on macOS, I noticed two commonly used flags were missing:

$ mount
/dev/disk3s1s1 on / (apfs, sealed, local, read-only, journaled)
/dev/disk3s5 on /System/Volumes/Data (apfs, local, journaled, nobrowse, protect)
/dev/disk3s7 on /nix (apfs, local, nosuid, journaled, noatime, nobrowse, protect)

The local and protect flags were not being parsed.

Changes

Added checks for two mount flags in PartitionsWithContext():

• MNT_LOCAL - indicates local (non-network) filesystem
• MNT_CPROTECT - indicates Data Protection is enabled (FileVault)

Testing

Manually tested on macOS by comparing output with the native mount command. The flags now appear correctly in partition options.

[shirou]

Thank you for your PR.
I have confirmed those flags in sys/unix. LGTM!