feat(acp): adopt codex-acp 1.10.0 background terminals

Bump the pinned adapter 1.8.0 -> 1.10.0 and take the AIR `asyncTasks`
channel it added.

codex now publishes its background terminals on the same lifecycle
claude-agent-acp does, gated on the client advertising the capability, so
`build_client_capabilities` sends `["sessionFailure", "asyncTasks"]` to
both. Everything downstream is already agent-agnostic: the live task
strip, the `_session/async_task/stop` control and the idle-sweep
keepalive light up for codex with no further wiring.

Without the capability the launching `execute` tool call sits at
`in_progress` for the rest of the connection with nothing to explain it.
With it, codex marks that call
`_meta.jetbrains.air.asyncTasks.backgrounded`; the command card reads it
(`toolCallMovedToBackground`) and badges it "Background" for as long as
the call is unsettled.

Also claim codex-acp 1.9.0's connection-level `_auth/status_update`.
Nothing consumes the payload, but the notification carries no
`sessionId`, so leaving it unhandled would make sacp log a rejection and
write a JSON-RPC error notification back to the agent for every push.