PR 39 closes the gap. New IsElevatedAdministratorOnWindows static helper (Windows-only via RuntimeInformation.IsOSPlatform; non-Windows hosts return false and let the prerequisite probe own the skip-with-reason path) checks WindowsPrincipal.IsInRole(WindowsBuiltInRole.Administrator) on the current process token. When true, InitializeAsync short-circuits to a SkipReason that names the cause directly: 'elevated token's Admins group membership trumps the allow rule — re-run from a NORMAL (non-admin) PowerShell window'. Catches and swallows any probe-side exception so a Win32 oddity can't crash the test fixture; failed probe falls through to the regular prerequisite path. The check fires BEFORE AvevaPrerequisites.CheckAllAsync runs because the prereq probe's own pipe connect hits the same admin-deny and surfaces UnauthorizedAccessException with no context. Short-circuiting earlier saves the 10-second probe + produces a single actionable line. Tests — verified manually from an elevated bash session against the just-installed OtOpcUaGalaxyHost service: skip message reads 'Test host is running with elevated (Administrators) privileges, but the OtOpcUaGalaxyHost named-pipe ACL explicitly denies Administrators per the IPC security design (decision #76 / PipeAcl.cs). Re-run from a NORMAL (non-admin) PowerShell window — even when your user is already in the pipe's allow list, the elevated token's Admins group membership trumps the allow rule.' Proxy.Tests Unit: 17 pass / 0 fail (unchanged — fixture change is non-breaking; existing tests don't run as admin in normal CI flow). Build clean. Bonus: gitignored .local/ directory (a previous direct commit on local v2 that I'm now landing here) so per-install secrets like the Galaxy.Host shared-secret file don't leak into the repo. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>