fix: enforce strict tool-call pairing across chat paths

pkg/agent/loop.go

@@ -442,7 +442,10 @@ func (al *AgentLoop) GetSessionHistory(sessionKey string) []providers.Message {
 }
 
 func (al *AgentLoop) processMessage(ctx context.Context, msg bus.InboundMessage) (string, error) {
-	msg.SessionKey = "main"
+	msg.SessionKey = strings.TrimSpace(msg.SessionKey)
+	if msg.SessionKey == "" {
+		msg.SessionKey = "main"
+	}
 	unlock := al.lockSessionRun(msg.SessionKey)
 	defer unlock()
 	// Add message preview to log
@@ -908,20 +911,6 @@ func (al *AgentLoop) processSystemMessage(ctx context.Context, msg bus.InboundMe
 		})
 
 		if err != nil {
-			errMsg := strings.ToLower(err.Error())
-			if strings.Contains(errMsg, "no tool call found for function call output") {
-				logger.WarnCF("agent", "System message hit orphan tool-call chain, retry with fresh context", map[string]interface{}{"iteration": iteration, "session": sessionKey})
-				messages = al.contextBuilder.BuildMessages(
-					nil,
-					"",
-					msg.Content,
-					nil,
-					originChannel,
-					originChatID,
-					responseLang,
-				)
-				continue
-			}
 			logger.ErrorCF("agent", "LLM call failed in system message",
 				map[string]interface{}{
 					"iteration": iteration,