50fd7be70dcd63e3cddba036aefffb813f44b010
Agent 'Close' (agent-close) sent a single SIGTERM via Session.Kill and never escalated, so an agent that traps/ignores SIGTERM (e.g. opencode) stayed in the running tab bar until the user closed it again. Add Session.Terminate, which reuses terminateAndWait (SIGTERM, wait, then SIGKILL) but preserves the session entry so the exited pane stays readable, and route handleChildClose's agent path through it in a goroutine to keep the UI responsive during the stop timeout. Resolves the opencode double-close TODO item.
Description
Terminal-based agent orchestration shell. Named after my dog.