## Why
Windows control sockets need a rendezvous directory that cannot be accessed or
replaced by another user while the listener is active.
## What changed
- Create socket directories with a protected, inheritable, current-user-only
DACL, and reject existing directories with broader permissions.
- Validate socket paths without following a junction at the rendezvous
directory, and pin the directory through listener cleanup to prevent
replacement after validation.
- Add a Windows peer check that verifies the kernel-reported peer process uses
the current user's non-elevated token.
- Document the Windows requirements for custom control socket paths.
## Testing
Add Windows coverage for ACL inheritance and rejection, junction and volume-root
rejection, extended-length paths, directory pinning, and elevated peer rejection.
GitOrigin-RevId: cc8dd76e5732c288f6346cfd6138051188533bfa
