Add a pause that holds an agent after its current step

internal/agents/inbox.go

@@ -304,6 +304,11 @@ func (m *Manager) Deliver(ctx context.Context, sessionID string) error {
 	unlock := m.lockDelivery(sessionID)
 	defer unlock()
 
+	if m.isPaused(sessionID) {
+		slog.Info("deliver held: session paused", "session", sessionID)
+		return nil
+	}
+
 	sess, err := m.store.GetSession(ctx, sessionID)
 	if err != nil {
 		return err
@@ -400,6 +405,9 @@ func (m *Manager) deliverMidTurn(ctx context.Context, l *live) midTurn {
 	unlock := m.lockDelivery(l.id)
 	defer unlock()
 
+	if m.isPaused(l.id) {
+		return midTurn{}
+	}
 	discard, err := m.store.GetDiscard(ctx, l.taskID)
 	if err != nil {
 		slog.Error("read discard state", "task", l.taskID, "err", err)
@@ -428,6 +436,23 @@ func (m *Manager) deliverMidTurn(ctx context.Context, l *live) midTurn {
 	return mt
 }
 
+func (m *Manager) midTurnWaiting(ctx context.Context, l *live) bool {
+	inputs, err := m.store.TaskInputs(ctx, l.taskID, l.member)
+	if err != nil {
+		slog.Error("list queued messages", "session", l.id, "err", err)
+		return false
+	}
+	if len(inputs) > 0 {
+		return true
+	}
+	pending, err := m.store.Undelivered(ctx, l.id)
+	if err != nil {
+		slog.Error("list undelivered responses", "session", l.id, "err", err)
+		return false
+	}
+	return len(pending) > 0
+}
+
 func (m *Manager) restoreMidTurn(ctx context.Context, l *live, mt midTurn) {
 	if len(mt.taskInputs) > 0 {
 		err := m.store.RestoreTaskInputs(ctx, mt.taskInputs)