The whenIdle() JSDoc cited "a closing ACP connection" as a non-owner that
awaits whenIdle(). That is false against the code: ACP OWNS its agent handles
and tears them down via rec.dispose()/handle.dispose() (quiesce() at
packages/ui/acp/src/index.ts:666-686), never whenIdle(). The only whenIdle()
consumers are tests (acp dispose/turns/edges specs, agent specs) — which is
genuinely why the primitive stays (a test harness programs against the seam),
but the contract doc must not claim a production ACP path uses it.
Replace the parenthetical with truthful non-owning observers (a test awaiting a
turn to settle, a monitor) and state explicitly that an OWNER does not need
whenIdle() because AgentHandle.dispose() already awaits the loop-exit promise.
- packages/core/agent/src/types.ts: the Agent.whenIdle() contract JSDoc.
- docs/core-data-structures/core.md: the type-equiv mirror (re-copied verbatim).
- Regenerate the cordis catalog (whenIdle source line shifted).