The native arm64 client follows steamdeck_publicbeta, so a Valve beta
regression reaches every user at once. If the repaired beta client is still
started twice without being shown, or the beta manifest carries no arm64
client, droiddeck-steam-install now installs steamdeck_stable, keeps it, and
logs why (listing the manifest's blocks in the second case). The session asks
the installer for the channel, so -clientbeta and package/beta stay in sync.
BL_STEAM_CHANNEL or ~/.config/droiddeck/steam-channel (beta|stable) pins it.
Valve's 2026-10-15 beta moved the x86 client into a Steam Runtime container.
In case the arm64 client follows, its session now exports
STEAM_STEAMRT_RECURSION_GUARD=1 and, only if steamrtarm64 carries pv-runtime
or a steam-runtime-check-requirements probe, starts it through the same
steamrt shim the x86-64 client uses (now droiddeck-steamrt-shim) and logs it.