fix(cron): route cron jobs to correct agent and publish response to channel

[securityguy]

Problem

Two separate bugs prevented cron jobs from delivering agent responses to the correct channel:

1. Peer binding never matched for cron jobs

ProcessDirectWithChannel constructed an InboundMessage but never set the Peer field. As a result, bindings that match on peer (the standard pattern for routing messages to a specific agent by channel) never fired — cron jobs always fell through to the default agent regardless of the configured binding.

2. Agent response was silently discarded

Even after routing worked, the agent's response was thrown away. In CronTool.ExecuteJob, the deliver=false branch called ProcessDirectWithChannel and then:

// Response is automatically sent via MessageBus by AgentLoop
_ = response // Will be sent by AgentLoop

This comment is incorrect. ProcessDirectWithChannel bypasses the Run loop entirely — nothing ever published the response to the bus. The deliver=true and command branches already called msgBus.PublishOutbound directly; the deliver=false branch simply forgot to.

Fix

pkg/agent/loop.go — set Peer on the inbound message in ProcessDirectWithChannel so peer-based bindings resolve correctly:

if chatID != "" && chatID != "direct" {
    msg.Peer = bus.Peer{Kind: "channel", ID: chatID}
}

pkg/tools/cron.go — publish the agent response after ProcessDirectWithChannel returns:

if response != "" {
    pubCtx, pubCancel := context.WithTimeout(context.Background(), 5*time.Second)
    defer pubCancel()
    t.msgBus.PublishOutbound(pubCtx, bus.OutboundMessage{
        Channel: channel,
        ChatID:  chatID,
        Content: response,
    })
}