Branch semantics kept where main and PM disagree: update_cmd_deps.py,
constraints-termux.txt, the Electron update-api-check module and the
post-swap hand-off test stay deleted; the pending-fleet-restart catch-up
and the local_runtime tag/download ladder stay retired (PM owns engines).
Ported from main onto the branch's shape: profile_scoped_chore for the
auto-archive and plugin-update housekeeping chores, the local-runtime
cross-process boot lock and residency cap, the checkpoint tmp_pack sweep,
the cua daemon-liveness status probe, the remote-served Desktop update
flag (posix.sh / windows.ps1), sign-in for env-pinned remote gateways
(urlDisabled on RemoteSetupFields), the uvloop extra split (uvicorn
without [standard]), and the umask-scoping spawn test.
uv.lock regenerated with pm.build_env --lock-only; new utf-8 reads from
main switched to utf-8-sig (check-windows-footguns).
9f2ba1b74d