Ship the portable X11 bundle lifecycle

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'

docs/x11-ga/README.md

@@ -33,7 +33,7 @@ The GA support promise for Aman should be:
 
 - Linux desktop sessions running X11.
 - Mainstream distros with `systemd --user` available.
-- System `python3` 3.10+ available for the portable installer.
+- System CPython `3.10`, `3.11`, or `3.12` available for the portable installer.
 - Runtime dependencies installed from the distro package manager.
 - Service mode is the default end-user mode.
 - Foreground `aman run` remains a support and debugging path, not the primary daily-use path.
@@ -87,7 +87,11 @@ Any future docs, tray copy, and release notes should point users to this same se
   the GA contract; `docs/release-checklist.md` now includes GA signoff gates;
   CLI help text now matches the same service/support language.
 - [ ] [Milestone 2: Portable Install, Update, and Uninstall](./02-portable-install-update-uninstall.md)
-  Build one reliable end-user lifecycle that works across mainstream X11 distros.
+  Implementation landed on 2026-03-12: the portable bundle, installer,
+  uninstaller, docs, and automated lifecycle tests are in the repo. Leave this
+  milestone open until the representative distro rows in
+  [`portable-validation-matrix.md`](./portable-validation-matrix.md) are filled
+  with real manual validation evidence.
 - [ ] [Milestone 3: Runtime Reliability and Diagnostics](./03-runtime-reliability-and-diagnostics.md)
   Make startup, failure handling, and recovery predictable.
 - [ ] [Milestone 4: First-Run UX and Support Docs](./04-first-run-ux-and-support-docs.md)