fix: handle slash commands instantly during long LLM processing

Split Run() into a dispatcher (main goroutine) and an LLM worker
(background goroutine). The dispatcher always consumes messages and
handles commands like /todo, /skills, /session immediately, even
while the LLM worker is busy with a long tool-call chain.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

pkg/agent/loop.go

@@ -156,25 +156,68 @@ func registerSharedTools(cfg *config.Config, msgBus *bus.MessageBus, registry *A
 func (al *AgentLoop) Run(ctx context.Context) error {
 	al.running.Store(true)
 
+	// LLM work is dispatched to a background worker so the main loop
+	// stays free to handle slash commands (/todo, /skills, …) instantly,
+	// even while a long tool-call chain is running.
+	llmQueue := make(chan bus.InboundMessage, 10)
+	workerDone := make(chan struct{})
+	go func() {
+		defer close(workerDone)
+		al.llmWorker(ctx, llmQueue)
+	}()
+	defer func() {
+		close(llmQueue)
+		<-workerDone
+	}()
+
 	for al.running.Load() {
 		select {
 		case <-ctx.Done():
 			return nil
 		default:
+		}
+
 		msg, ok := al.bus.ConsumeInbound(ctx)
 		if !ok {
 			continue
 		}
 
+		// Fast path: handle slash commands immediately without blocking the LLM worker.
+		if response, handled := al.handleCommand(ctx, msg); handled {
+			if response != "" {
+				al.bus.PublishOutbound(bus.OutboundMessage{
+					Channel: msg.Channel,
+					ChatID:  msg.ChatID,
+					Content: response,
+				})
+			}
+			continue
+		}
+
+		// Dispatch to LLM worker
+		select {
+		case llmQueue <- msg:
+		case <-ctx.Done():
+			return nil
+		}
+	}
+
+	return nil
+}
+
+// llmWorker processes LLM messages sequentially in a background goroutine.
+func (al *AgentLoop) llmWorker(ctx context.Context, queue <-chan bus.InboundMessage) {
+	for msg := range queue {
+		if ctx.Err() != nil {
+			return
+		}
+
 		response, err := al.processMessage(ctx, msg)
 		if err != nil {
 			response = fmt.Sprintf("Error processing message: %v", err)
 		}
 
 		if response != "" {
-				// Check if the message tool already sent a response during this round.
-				// If so, skip publishing to avoid duplicate messages to the user.
-				// Use default agent's tools to check (message tool is shared).
 			alreadySent := false
 			defaultAgent := al.registry.GetDefaultAgent()
 			if defaultAgent != nil {
@@ -194,9 +237,6 @@ func (al *AgentLoop) Run(ctx context.Context) error {
 			}
 		}
 	}
-	}
-
-	return nil
 }
 
 func (al *AgentLoop) Stop() {