fix(session): restore thread and legacy compatibility

pkg/agent/loop.go

@@ -805,6 +805,8 @@ func outboundTurnMetadata(
 func outboundMessageForTurn(ts *turnState, content string) bus.OutboundMessage {
 	agentID, sessionKey, scope := outboundTurnMetadata(ts.agent.ID, ts.sessionKey, ts.opts.Dispatch.SessionScope)
 	return bus.OutboundMessage{
+		Channel: ts.channel,
+		ChatID:  ts.chatID,
 		Context: outboundContextFromInbound(
 			ts.opts.Dispatch.InboundContext,
 			ts.channel,
@@ -2827,6 +2829,8 @@ turnLoop:
 					parts = append(parts, part)
 				}
 				outboundMedia := bus.OutboundMediaMessage{
+					Channel: ts.channel,
+					ChatID:  ts.chatID,
 					Context: outboundContextFromInbound(
 						ts.opts.Dispatch.InboundContext,
 						ts.channel,

pkg/agent/steering.go

@@ -3,6 +3,7 @@ package agent
 import (
 	"context"
 	"fmt"
+	"sort"
 	"strings"
 	"sync"
 
@@ -319,7 +320,9 @@ func (al *AgentLoop) agentForSession(sessionKey string) *AgentInstance {
 		return nil
 	}
 
-	for _, agentID := range registry.ListAgentIDs() {
+	agentIDs := registry.ListAgentIDs()
+	sort.Strings(agentIDs)
+	for _, agentID := range agentIDs {
 		agent, ok := registry.GetAgent(agentID)
 		if !ok || agent == nil {
 			continue
@@ -331,7 +334,6 @@ func (al *AgentLoop) agentForSession(sessionKey string) *AgentInstance {
 		if scopedAgent, ok := registry.GetAgent(resolvedAgentID); ok {
 			return scopedAgent
 		}
-		return agent
 	}
 
 	return registry.GetDefaultAgent()