Like others here I created my own terminal multiplexer as well. Daemon that holds all sessions, seamless binary upgrades so those sessions never get lost, everything recorded so recovery is always possible, thin client mode so laptop has a native app that connects to daemon, and a wasm responsive webui with transcription so I can carry on with sessions from phone. Claude/codex sessions started with a uuid so they can be killed/resumed at will (mine autosleep after 12h inactivity to free resouces). CLI allows agent control of everything for a harness independent implementation of claude's channels. A few friends have forked and adopted it as their daily driver. Similar organization to herdr wrt spaces to organize sessions. Optimized for speed/bandwidth when running in thin client mode.
https://github.com/zackham/seance