Auto-select single login-capable channel, harden channel ids, catalog-backed install fallback.
Channel Auth Fixes
- Auto-select —
channels login/logoutauto-select the single configured login-capable channel - Channel ids — Hardened against prototype-chain and control-character abuse
- Catalog fallback — Clean fallback to catalog-backed channel installs
Channel auth works again for single-channel setups and on-demand channel installs.