onRouteFailure marker always lands in the primary agent's window #188

The [discord-send-failed] marker for a failed speech route always lands in the primary agent's window, even when another agent authored the reply.

• ChannelRegistry passes conversationId (the speaking agent) to the callback:

  agent-framework/src/mcpl/channel-registry.ts

  Line 2850 in 59a2a02

  this.onRouteFailure?.({ conversationId, channelId, reason, textLen: text.length });

• The framework handler destructures only { channelId, reason, textLen } and calls this.addMessage(...) with no forAgent:

  agent-framework/src/framework.ts

  Lines 11864 to 11889 in 59a2a02

  	onRouteFailure: ({ channelId, reason, textLen }) => {
  	try {
  	// Render a human-readable channel name when we can — a bare
  	// snowflake in the marker is unresolvable for the agent (the
  	// 2026-07-21 incident read as "a stale artifact", not a live
  	// failure). The marker is `system: true`, so it is never
  	// conversational and never influences routing.
  	const label = channelId
  	? this.channelRegistry?.getDescriptor(channelId)?.label
  	: undefined;
  	const where = channelId
  	? label && label !== channelId
  	? `${label.startsWith('#') ? label : `#${label}`} (${channelId})`
  	: channelId
  	: 'the channel';
  	this.addMessage(
  	'user',
  	[{
  	type: 'text',
  	text: `[discord-send-failed] Your previous reply (${textLen} chars) could not be delivered to ${where} (${reason}). It was saved to your archive but the human did not receive it.`,
  	}],
  	{ system: true, kind: 'discord-send-failed', channelId: channelId ?? '', reason },
  	);
  	} catch (err) {
  	console.error('onRouteFailure: failed to record send-failure marker:', err);
  	}

• An untargeted addMessage resolves to the primary agent:

  agent-framework/src/framework.ts

  Lines 11180 to 11184 in 59a2a02

  	const agent = opts?.forAgent
  	? this.agents.get(opts.forAgent)
  	: this.primaryAgentName
  	? this.agents.get(this.primaryAgentName)
  	: this.agents.values().next().value;

Effect: in a multi-agent setup, a non-primary agent whose reply failed to route never sees the "your previous reply" notice, while the primary agent gets a notice about a reply it never wrote.

Suggested direction: take conversationId in the handler and pass { forAgent: conversationId } when it names a registered agent, falling back to the primary otherwise.

This bug is already on main. Greptile raised it on #163 because that PR adds another failure reason (missing receipt) that goes through the same handler.