Live producer for agent-initiated plan→build (#520).
Pixir.ACP.Server.runtime_config_change/3 is the presenter wire. This module
is the caller: when a plan-mode Turn records a plan, Pixir advertises build
so the client picker moves without a session/set_mode round-trip.
CLI and other non-ACP Turns have no acp_runtime binding and are a no-op.
A Turn that is already in build does not emit a no-op flip. The Server helper
also drops an unchanged advertised mode, so a second update_plan in the same
plan-mode Turn does not duplicate the wire update.
Summary
Functions
Advertise plan→build for the ACP session bound on this tool context.
Types
@type acp_runtime() :: %{server: GenServer.server(), acp_sid: String.t()}
Functions
Advertise plan→build for the ACP session bound on this tool context.
Called from Pixir.Tools.UpdatePlan after a plan is recorded. Returns
{:ok, :queued} when a change was handed to the Server, or :ok when there
is no ACP binding or the Turn is not in plan mode.