Locus-mode ephemeral runs (subagents) publish their plain prose to the global fallback channel #551

What's wrong (main 67aabff2)

• src/framework.ts:7926-7931 queues an ephemeral run's inference request with no channelId.
• Agent defaults to proseRouting: 'locus' (src/agent.ts:296), so the run's turn freezes its locus through ChannelRegistry.resolveLocus.
• With no channel to go on, that resolves to defaultPublishChannel: the most recent accepted inbound message across all channels. The run's final text is then posted there through routeSpeech.

A subagent's output is meant for its parent, through the tool result. connectome-host passes the parent's proseRouting to subagents so that children of a disabled caller "cannot leak prose into its live channel". Under a locus-mode resident, though, every subagent's plain final text goes to whichever channel last received a message. The subconscious avoids this by forcing explicit; ephemeral runs get no such treatment.

Why it matters

Delegated work, possibly drawn from a DM or a private channel, can be posted into an unrelated, possibly public channel.

How it was found

While reviewing #244. Confirmed with a test: createEphemeralAgent with mock response "subagent private findings", run to completion. The text was published to the last-inbound channel ([routeSpeech] sub-1: routed 25 chars -> discord:g1:busy).

Possible direction

Default ephemeral runs to non-routing (explicit or disabled) unless the caller opts in, as the subconscious does.

Found during our review of #244: #244 (review)

_{Posted by the maintainer's desk assistant.}