fix(agent): implement Critical flag, complete tools.SubTurnConfig, remove redundant subTurnResults

- Critical flag was declared but never acted on; non-critical SubTurns
  now break out of the iteration loop when IsParentEnded() returns true
- tools.SubTurnConfig was missing Critical/Timeout/MaxContextRunes,
  making those fields unreachable from the tools layer; added fields and
  wired them through AgentLoopSpawner.SpawnSubTurn
- Removed subTurnResults sync.Map from AgentLoop — it was a redundant
  alias for the same channel already stored in turnState.pendingResults;
  dequeuePendingSubTurnResults now reads directly via activeTurnStates
- Replace hardcoded concurrencySem size 5 with maxConcurrentSubTurns constant
- Update affected tests to match new dequeuePendingSubTurnResults API

pkg/agent/loop.go

@@ -49,7 +49,6 @@ type AgentLoop struct {
 	cmdRegistry      *commands.Registry
 	mcp              mcpRuntime
 	steering         *steeringQueue
-	subTurnResults   sync.Map     // key: sessionKey (string), value: chan *tools.ToolResult
 	activeTurnStates sync.Map     // key: sessionKey (string), value: *turnState
 	subTurnCounter   atomic.Int64 // Counter for generating unique SubTurn IDs
 	mu               sync.RWMutex
@@ -1001,7 +1000,7 @@ func (al *AgentLoop) runAgentLoop(
 			session:              agent.Sessions,
 			initialHistoryLength: len(agent.Sessions.GetHistory("")), // Snapshot for rollback on hard abort
 			pendingResults:       make(chan *tools.ToolResult, 16),
-			concurrencySem:       make(chan struct{}, 5), // maxConcurrentSubTurns
+			concurrencySem:       make(chan struct{}, maxConcurrentSubTurns), // maxConcurrentSubTurns
 		}
 		ctx = withTurnState(ctx, rootTS)
 		ctx = WithAgentLoop(ctx, al) // Inject AgentLoop for tool access
@@ -1010,10 +1009,6 @@ func (al *AgentLoop) runAgentLoop(
 		// Register this root turn state so HardAbort can find it
 		al.activeTurnStates.Store(opts.SessionKey, rootTS)
 		defer al.activeTurnStates.Delete(opts.SessionKey)
-
-		// Ensure the parent's pending results channel is cleaned up when this root turn finishes
-		defer al.unregisterSubTurnResultChannel(rootTS.turnID)
-		al.registerSubTurnResultChannel(rootTS.turnID, rootTS.pendingResults)
 	}
 
 	// 0. Record last channel for heartbeat notifications (skip internal channels and cli)
@@ -1220,15 +1215,19 @@ func (al *AgentLoop) runLLMIteration(
 		// This is only relevant for SubTurns (turnState with parentTurnState != nil).
 		// If parent ended and this SubTurn is not Critical, exit gracefully.
 		if ts := turnStateFromContext(ctx); ts != nil && ts.IsParentEnded() {
-			logger.InfoCF("agent", "Parent turn ended, SubTurn continues or exits", map[string]any{
+			if !ts.critical {
+				logger.InfoCF("agent", "Parent turn ended, non-critical SubTurn exiting gracefully", map[string]any{
+					"agent_id":  agent.ID,
+					"iteration": iteration,
+					"turn_id":   ts.turnID,
+				})
+				break
+			}
+			logger.InfoCF("agent", "Parent turn ended, critical SubTurn continues running", map[string]any{
 				"agent_id":  agent.ID,
 				"iteration": iteration,
 				"turn_id":   ts.turnID,
 			})
-			// For now, we continue running. The Critical flag check is handled
-			// at SubTurnConfig level in spawnSubTurn. Here we just log and continue.
-			// If this SubTurn should exit gracefully, it would have been cancelled
-			// by its own timeout or the caller would have handled it.
 		}
 
 		// Inject pending steering messages into the conversation context

pkg/agent/steering.go

@@ -192,14 +192,13 @@ func (al *AgentLoop) Continue(ctx context.Context, sessionKey, channel, chatID s
 
 // dequeuePendingSubTurnResults polls the SubTurn result channel for the given
 // session and returns all available results without blocking.
-// Returns nil if no channel is registered for this session.
+// Returns nil if no active turn state exists for this session.
 func (al *AgentLoop) dequeuePendingSubTurnResults(sessionKey string) []*tools.ToolResult {
-	chInterface, ok := al.subTurnResults.Load(sessionKey)
+	tsInterface, ok := al.activeTurnStates.Load(sessionKey)
 	if !ok {
 		return nil
 	}
-
+	ts, ok := tsInterface.(*turnState)
-	ch, ok := chInterface.(chan *tools.ToolResult)
 	if !ok {
 		return nil
 	}
@@ -207,7 +206,7 @@ func (al *AgentLoop) dequeuePendingSubTurnResults(sessionKey string) []*tools.To
 	var results []*tools.ToolResult
 	for {
 		select {
-		case result := <-ch:
+		case result := <-ts.pendingResults:
 			if result != nil {
 				results = append(results, result)
 			}
@@ -217,17 +216,6 @@ func (al *AgentLoop) dequeuePendingSubTurnResults(sessionKey string) []*tools.To
 	}
 }
 
-// registerSubTurnResultChannel registers a SubTurn result channel for the given session.
-// This allows the parent loop to poll for results from child SubTurns.
-func (al *AgentLoop) registerSubTurnResultChannel(sessionKey string, ch chan *tools.ToolResult) {
-	al.subTurnResults.Store(sessionKey, ch)
-}
-
-// unregisterSubTurnResultChannel removes the SubTurn result channel for the given session.
-func (al *AgentLoop) unregisterSubTurnResultChannel(sessionKey string) {
-	al.subTurnResults.Delete(sessionKey)
-}
-
 // ====================== Hard Abort ======================
 
 // HardAbort immediately cancels the running agent loop for the given session,

pkg/agent/subturn.go

@@ -191,6 +191,9 @@ func (s *AgentLoopSpawner) SpawnSubTurn(ctx context.Context, cfg tools.SubTurnCo
 		SystemPrompt:    cfg.SystemPrompt,
 		MaxTokens:       cfg.MaxTokens,
 		Async:           cfg.Async,
+		Critical:        cfg.Critical,
+		Timeout:         cfg.Timeout,
+		MaxContextRunes: cfg.MaxContextRunes,
 	}
 
 	return spawnSubTurn(ctx, s.al, parentTS, agentCfg)
@@ -277,6 +280,7 @@ func spawnSubTurn(ctx context.Context, al *AgentLoop, parentTS *turnState, cfg S
 	childTS := newTurnState(childCtx, childID, parentTS)
 	// Set the cancel function so Finish(true) can trigger hard cancellation
 	childTS.cancelFunc = cancel
+	childTS.critical = cfg.Critical
 
 	// IMPORTANT: Put childTS into childCtx so that code inside runTurn can retrieve it
 	childCtx = withTurnState(childCtx, childTS)

pkg/agent/subturn_test.go

@@ -315,11 +315,6 @@ func TestSubTurnResultChannelRegistration(t *testing.T) {
 	}
 
 	_, _ = spawnSubTurn(context.Background(), al, parent, cfg)
-
-	// After spawn completes: channel should be unregistered (defer cleanup in spawnSubTurn)
-	if _, ok := al.subTurnResults.Load(parent.turnID); ok {
-		t.Error("channel should be unregistered after spawnSubTurn completes")
-	}
 }
 
 // ====================== Extra Independent Test: Dequeue Pending SubTurn Results ======================
@@ -328,21 +323,27 @@ func TestDequeuePendingSubTurnResults(t *testing.T) {
 	defer cleanup()
 
 	sessionKey := "test-session-dequeue"
-	ch := make(chan *tools.ToolResult, 4)
 
-	// Register channel manually
+	// Empty (no turnState registered) returns nil
-	al.registerSubTurnResultChannel(sessionKey, ch)
-	defer al.unregisterSubTurnResultChannel(sessionKey)
-
-	// Empty channel returns nil
 	if results := al.dequeuePendingSubTurnResults(sessionKey); len(results) != 0 {
 		t.Errorf("expected empty results, got %d", len(results))
 	}
 
+	// Register a turnState so dequeuePendingSubTurnResults can find it
+	ts := &turnState{
+		ctx:            context.Background(),
+		turnID:         sessionKey,
+		depth:          0,
+		session:        &ephemeralSessionStore{},
+		pendingResults: make(chan *tools.ToolResult, 4),
+	}
+	al.activeTurnStates.Store(sessionKey, ts)
+	defer al.activeTurnStates.Delete(sessionKey)
+
 	// Put 3 results in
-	ch <- &tools.ToolResult{ForLLM: "result-1"}
+	ts.pendingResults <- &tools.ToolResult{ForLLM: "result-1"}
-	ch <- &tools.ToolResult{ForLLM: "result-2"}
+	ts.pendingResults <- &tools.ToolResult{ForLLM: "result-2"}
-	ch <- &tools.ToolResult{ForLLM: "result-3"}
+	ts.pendingResults <- &tools.ToolResult{ForLLM: "result-3"}
 
 	results := al.dequeuePendingSubTurnResults(sessionKey)
 	if len(results) != 3 {
@@ -357,8 +358,8 @@ func TestDequeuePendingSubTurnResults(t *testing.T) {
 		t.Errorf("expected empty after drain, got %d", len(results))
 	}
 
-	// Unregistered session returns nil
+	// After removing from activeTurnStates, returns nil
-	al.unregisterSubTurnResultChannel(sessionKey)
+	al.activeTurnStates.Delete(sessionKey)
 	if results := al.dequeuePendingSubTurnResults(sessionKey); results != nil {
 		t.Error("expected nil for unregistered session")
 	}
@@ -766,15 +767,21 @@ func TestFinalPollCapturesLateResults(t *testing.T) {
 	defer cleanup()
 
 	sessionKey := "test-session-final-poll"
-	ch := make(chan *tools.ToolResult, 4)
 
-	// Register the channel
+	// Register a turnState
-	al.registerSubTurnResultChannel(sessionKey, ch)
+	ts := &turnState{
-	defer al.unregisterSubTurnResultChannel(sessionKey)
+		ctx:            context.Background(),
+		turnID:         sessionKey,
+		depth:          0,
+		session:        &ephemeralSessionStore{},
+		pendingResults: make(chan *tools.ToolResult, 4),
+	}
+	al.activeTurnStates.Store(sessionKey, ts)
+	defer al.activeTurnStates.Delete(sessionKey)
 
 	// Simulate results arriving after last iteration poll
-	ch <- &tools.ToolResult{ForLLM: "result 1"}
+	ts.pendingResults <- &tools.ToolResult{ForLLM: "result 1"}
-	ch <- &tools.ToolResult{ForLLM: "result 2"}
+	ts.pendingResults <- &tools.ToolResult{ForLLM: "result 2"}
 
 	// Dequeue should capture both results
 	results := al.dequeuePendingSubTurnResults(sessionKey)
@@ -1414,8 +1421,6 @@ func TestContextWrapping_SingleLayer(t *testing.T) {
 	t.Log("Context wrapping test passed - no redundant layers detected")
 }
 
-
-
 // TestSyncSubTurn_NoChannelDelivery verifies that synchronous sub-turns
 // do NOT deliver results to the pendingResults channel (only return directly).
 func TestSyncSubTurn_NoChannelDelivery(t *testing.T) {
@@ -1526,8 +1531,6 @@ func TestAsyncSubTurn_ChannelDelivery(t *testing.T) {
 	}
 }
 
-
-
 // TestGrandchildAbort_CascadingCancellation verifies that when a grandparent turn
 // is hard aborted, the cancellation cascades down to grandchild turns.
 func TestGrandchildAbort_CascadingCancellation(t *testing.T) {

pkg/agent/turn_state.go

@@ -54,6 +54,10 @@ type turnState struct {
 	// to continue running (Critical=true) or exit gracefully (Critical=false).
 	parentEnded atomic.Bool
 
+	// critical indicates whether this SubTurn should continue running after
+	// the parent turn finishes gracefully. Set from SubTurnConfig.Critical.
+	critical bool
+
 	// parentTurnState holds a reference to the parent turnState.
 	// This allows child SubTurns to check if the parent has ended.
 	// Nil for root turns.

pkg/tools/subagent.go

@@ -23,6 +23,9 @@ type SubTurnConfig struct {
 	MaxTokens    int
 	Temperature  float64
 	Async        bool          // true for async (spawn), false for sync (subagent)
+	Critical     bool          // continue running after parent finishes gracefully
+	Timeout      time.Duration // 0 = use default (5 minutes)
+	MaxContextRunes int        // 0 = auto, -1 = no limit, >0 = explicit limit
 }
 
 type SubagentTask struct {