fix(hooks): restore direct message callback when hooks disabled

docs/hooks-plugin-examples.md

@@ -134,4 +134,5 @@ Recommended ordering:
 
 - Hook panics are recovered internally; one bad hook does not crash the loop.
 - Hook errors are logged and execution continues unless `Cancel` is set.
+- Observe-only hooks (`message_received`, `after_tool_call`, `llm_input`, `llm_output`, `session_start`, `session_end`) must treat events as read-only.
 - Keep hook handlers fast and non-blocking to avoid latency impact.

pkg/agent/loop.go

@@ -230,6 +230,17 @@ func (al *AgentLoop) SetHooks(h *hooks.HookRegistry) error {
 		if agent, ok := al.registry.GetAgent(agentID); ok {
 			if tool, ok := agent.Tools.Get("message"); ok {
 				if mt, ok := tool.(*tools.MessageTool); ok {
+					if h == nil {
+						mt.SetSendCallback(func(_ context.Context, channel, chatID, content string) error {
+							al.bus.PublishOutbound(bus.OutboundMessage{
+								Channel: channel,
+								ChatID:  chatID,
+								Content: content,
+							})
+							return nil
+						})
+						continue
+					}
 					mt.SetSendCallback(func(ctx context.Context, channel, chatID, content string) error {
 						if sent, reason := al.sendOutbound(ctx, bus.OutboundMessage{
 							Channel: channel,