mu-rkhj: event-driven dialogue receive — acked server→daemon push, no model-visible polling

[tcovert-c137]

Fixes mu-rkhj: inbound dialogue for mu sessions was a model-visible dialogue_poll long poll — the turn froze while it blocked, queued prompts wedged behind it, and a broadcast had nothing coherent to wait for. Operator standard (on the bead): event-driven wake only; poll completes when called; replies correlate by identifier, never adjacency. Routing decision: option 3, daemon-keyed subscription (peer ids mu:<daemon>:<session> route on the daemon segment).

mu-dialogue server

• dialogue_subscribe {daemon_id} registers the calling connection for push; every unacked message for mu:<daemon_id>:* replays oldest-first on subscribe. Subscription replacement is always logged.
• say/fan_out push each row as a notifications/dialogue.message server-initiated notification over the standalone SSE stream. A send is not delivery (panel finding — notifications are unacknowledged): only the daemon's dialogue_ack marks delivered_at, after the message reached the session's input channel. At-least-once contract.
• The plumbing tools are not in tools/list (panel finding): discovery is the handshake's experimental: mu.dialoguePush capability, so no model/tool surface built from the listing ever sees them. The channel's open-trust posture (say/poll already accept any identity) is documented; real authn (peer handles / capability tokens) is recorded follow-up.
• A subscribed daemon's dialogue_poll degenerates to an immediate drain — push covers receive, waiting is meaningless. Unsubscribed peers (cc's out-of-band watcher) keep the long poll unchanged.
• Broadcast is fire-and-return; the thread id in the tool result is the correlation handle.

mu daemon

• Outbound MCP client: on_custom_notification parses the push and forwards it (with the connection's ack peer) to a serve-side router; import subscribes when the handshake advertises the capability, and the subscribed connection is held for the daemon's lifetime (an all-filtered import otherwise dropped it, killing the subscription — caught by the e2e).
• Router: dedups the at-least-once window by message id (256-LRU), injects AgentInput::DialogueMessage into the addressed session, and acks only after the input landed — unknown/dead sessions stay unacked and replay on the next subscribe. Router + held connections ride the transport closure via AbortOnDrop (mu-ad5x lesson).

mu-core

• AgentInput::DialogueMessage carries message_id + thread; the woken turn's motivation names them and instructs replying with session_thread=<thread> so responses pair by id regardless of arrival order.

Verification

• e2e (serve_smoke::z_rkhj_dialogue_push_wakes_session_no_polling): stub dialogue server advertising only the handshake capability (zero listed tools) → daemon subscribes at import → one pushed notification wakes the session, whose motivation carries sender/content/correlation → done has no ask receipts → the daemon acks the id.
• Server unit tests: ack-marks-exactly-once, undelivered-awaits-replay, migration idempotency, daemon-id parsing; loop test asserts the correlation handles reach the model. Full just ci green.

Gate

Three panel runs, each converging the diff: run 1 escalated with real findings (send≠delivery, unknown-session drops marked delivered, push/replay duplicate race, tool-surface exposure — all fixed above; one finding dismissed with evidence as hallucinated); run 2 narrowed to the tool-surface objection, fixed structurally; final run consensus approve in 2 rounds, all seats.

🤖 Generated with Claude Code

https://claude.ai/code/session_01REB3QZvP3arA2cLMVRgYam