Do my agents come back after I quit crystl?

Yes. A shard restored by crystl (whether from the session restore on relaunch or from an explicit resurrect) holds a deferred relaunch, and the first thing dispatched to it starts its agent on its own conversation before delivering the message. So a chat-dock message, a quest turn, a notification, or a crystl send reaches the agent you were talking to rather than landing in the shell underneath, and an overnight fan-out survives quitting the app. If a relaunch can’t happen, the shard reports ⚠ no agent — relaunch failed in crystl shards instead of looking healthy and silently swallowing what you send it. See resurrecting shards.