feat: add portable NexusOS CLI and packaging

management/ncp.cmd

@@ -12,17 +12,20 @@ REM exactly what this file exists to avoid.
 REM
 REM ASCII only, same rule as the .ps1 files - a test in tests/test_smoke.py enforces it.
 setlocal
-REM ncp.py pins its stdout to UTF-8 (it prints check marks and em-dashes, and a
+REM The CLI pins its stdout to UTF-8 (it prints check marks and em-dashes, and a
 REM redirected stdout would otherwise raise UnicodeEncodeError). A console still
 REM on codepage 437 renders those bytes as mojibake, so switch it to UTF-8 here.
 REM ponytail: chcp changes the calling console's codepage and does not restore
 REM it on exit. Harmless in practice; if that ever matters, set the console CP
-REM from inside ncp.py with ctypes SetConsoleOutputCP instead.
+REM from inside the CLI with ctypes SetConsoleOutputCP instead.
 chcp 65001 >nul 2>&1
 set "ROOT=%~dp0.."
 REM System Python fallback so backup/restore work before the venv exists; those
 REM delegate to the stdlib-only bin/sync.py. Mirrors the same fallback in ncp.ps1.
 set "PY=%ROOT%\Promethean\Scripts\python.exe"
 if not exist "%PY%" set "PY=python"
-"%PY%" "%ROOT%\management\ncp.py" %*
-exit /b %ERRORLEVEL%
+pushd "%ROOT%"
+"%PY%" -m management.cli %*
+set "NEXUS_EXIT=%ERRORLEVEL%"
+popd
+exit /b %NEXUS_EXIT%