On Windows the lifecycle hooks run via PowerShell, which does not expand
cmd.exe-style %CLAUDE_PLUGIN_ROOT%. The path was passed literally, so the hook
launcher could not find the script and both SessionStart and UserPromptSubmit
failed with exit code 1 (issue #19). Switch the two commandWindows entries to
$env:CLAUDE_PLUGIN_ROOT, keeping the working node + .js invocation.
Add a regression test that rejects cmd.exe %VAR% syntax in commandWindows and
asserts every hook command points at a script that actually ships in hooks/.
Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
