Module intervention 

Worker-side mid-run intervention delivery (NOI-6): the attempt back-index that routes a pushed neutral command to the live session that owns its target. Worker-side mid-run intervention delivery (NOI-6).

This is the WORKER half of the intervention routing path: a command routed operator -> server -> liminal PUSH arrives here and is delivered to the in-flight agent session that owns the target (workflow, activity, attempt), which applies it via AgentSession::intervene and returns a neutral ack.

Harness-neutral by construction

Nothing in this module names a harness, a wire protocol, or a concrete adapter. It speaks ONLY the neutral aion-core control vocabulary: an [InterventionCommand] in, an [InterventionOutcome] ack out. The command is delivered onto the session’s driver control channel (a ControlMessage), where spawn_agent drains it into the session and replies the ack — so the harness-specific translation stays behind the AgentSession trait, never here.

The attempt back-index (§6.4)

ControlRegistry is the worker’s (workflow, activity, attempt) -> session control channel back-index. A command whose target has no live entry — because the attempt finished, was superseded by a later attempt, or never ran here — is the attempt-scoped no-op: it returns [InterventionOutcome::stale_target], an honest NACK, never a panic. A command whose primitive the target session does not advertise returns [InterventionOutcome::capability_not_supported]. Neither is an error: they are two of the three locked outcome classes.

Structs

ControlRegistry

The worker’s attempt back-index: maps a live SessionKey to its session control leg, so a routed command reaches the exact in-flight attempt.

SessionGuard

Drop guard removing a session’s control leg from the ControlRegistry when the session ends, so the back-index tracks exactly the live sessions.

SessionKey

The (workflow, activity, attempt) key one running agent session is addressed by — the exact identity the design keys the whole intervention path on.