fix(cron): inject delivery context into cron job system prompt

Cron jobs ran in isolated sessions with no context about who requested
them or where to deliver responses. The agent would misroute responses
(e.g., using team_message instead of replying to the original chat).

- Inject ExtraSystemPrompt with job name, requester ID, and delivery
  target so the agent knows to produce content directly
- Pass client.UserID() in Web UI cron.create instead of empty string

cmd/gateway_cron.go

@@ -39,19 +39,37 @@ func makeCronJobHandler(sched *scheduler.Scheduler, msgBus *bus.MessageBus, cfg
 		// Resolve channel type for system prompt context.
 		channelType := resolveChannelType(channelMgr, channel)
 
+		// Build cron context so the agent knows delivery target and requester.
+		var extraPrompt string
+		if job.Payload.Deliver && job.Payload.Channel != "" && job.Payload.To != "" {
+			extraPrompt = fmt.Sprintf(
+				"[Cron Job]\nThis is scheduled job \"%s\" (ID: %s).\n"+
+					"Requester: user %s on channel \"%s\" (chat %s).\n"+
+					"Your response will be automatically delivered to that chat — just produce the content directly.",
+				job.Name, job.ID, job.UserID, job.Payload.Channel, job.Payload.To,
+			)
+		} else {
+			extraPrompt = fmt.Sprintf(
+				"[Cron Job]\nThis is scheduled job \"%s\" (ID: %s), created by user %s.\n"+
+					"Delivery is not configured — respond normally.",
+				job.Name, job.ID, job.UserID,
+			)
+		}
+
 		// Schedule through cron lane — scheduler handles agent resolution and concurrency
 		outCh := sched.Schedule(context.Background(), scheduler.LaneCron, agent.RunRequest{
-			SessionKey:  sessionKey,
+			SessionKey:        sessionKey,
-			Message:     job.Payload.Message,
+			Message:           job.Payload.Message,
-			Channel:     channel,
+			Channel:           channel,
-			ChannelType: channelType,
+			ChannelType:       channelType,
-			ChatID:      job.Payload.To,
+			ChatID:            job.Payload.To,
-			PeerKind:    peerKind,
+			PeerKind:          peerKind,
-			UserID:      job.UserID,
+			UserID:            job.UserID,
-			RunID:       fmt.Sprintf("cron:%s", job.ID),
+			RunID:             fmt.Sprintf("cron:%s", job.ID),
-			Stream:      false,
+			Stream:            false,
-			TraceName:   fmt.Sprintf("Cron [%s] - %s", job.Name, agentID),
+			ExtraSystemPrompt: extraPrompt,
-			TraceTags:   []string{"cron"},
+			TraceName:         fmt.Sprintf("Cron [%s] - %s", job.Name, agentID),
+			TraceTags:         []string{"cron"},
 		})
 
 		// Block until the scheduled run completes

internal/gateway/methods/cron.go

@@ -78,7 +78,7 @@ func (m *CronMethods) handleCreate(ctx context.Context, client *gateway.Client,
 		return
 	}
 
-	job, err := m.service.AddJob(params.Name, params.Schedule, params.Message, params.Deliver, params.Channel, params.To, params.AgentID, "")
+	job, err := m.service.AddJob(params.Name, params.Schedule, params.Message, params.Deliver, params.Channel, params.To, params.AgentID, client.UserID())
 	if err != nil {
 		client.SendResponse(protocol.NewErrorResponse(req.ID, protocol.ErrInvalidRequest, err.Error()))
 		return