Implement milestone 2 around a portable X11 release bundle instead of\nkeeping distro packages as the only end-user path.\n\nAdd make/package scripts plus a portable installer helper that builds the\ntarball, creates a user-scoped venv install, manages the user service, handles\nupgrade rollback, and supports uninstall with optional purge.\n\nFlip the end-user docs to the portable bundle, add a dedicated install guide\nand validation matrix, and leave the roadmap milestone open only for the\nremaining manual distro validation evidence.\n\nValidation: python3 -m py_compile src/*.py packaging/portable/portable_installer.py tests/test_portable_bundle.py; PYTHONPATH=src python3 -m unittest tests.test_portable_bundle; PYTHONPATH=src python3 -m unittest tests.test_aman_cli tests.test_diagnostics tests.test_portable_bundle; PYTHONPATH=src python3 -m unittest discover -s tests -p 'test_*.py'
