Method AttachRuntime

pkg/server/session_manager.go:205–214

AttachRuntime registers a pre-built runtime + session under sessionID so that subsequent calls (RunSession, Steer, Resume...) reuse it instead of building one from agentFilename. This is what lets a single in-process runtime be shared between the TUI and an HTTP control plane. The internal cancella

(ctx context.Context, sessionID string, rt runtime.Runtime, sess *session.Session)

// SSE streams and other lifetime-bound consumers use it (via
// [SessionManager.StreamEvents]) to terminate when the session is detached.
func (sm *SessionManager) AttachRuntime(ctx context.Context, sessionID string, rt runtime.Runtime, sess *session.Session) {
	ctx, cancel := context.WithCancel(context.WithoutCancel(ctx))
	sm.runtimeSessions.Store(sessionID, &activeRuntimes{
		runtime: rt,
		done:    ctx.Done(),
		cancel:  cancel,
		session: sess,
	})
	sm.markReady()
}

// GetSession retrieves a session by ID.
func (sm *SessionManager) GetSession(ctx context.Context, id string) (*session.Session, error) {