Drives a %Spectre.Turn{} decision to a delivered outcome.

Every host that consumes Spectre.turn/3 ends up writing the same loop: branch on the decision tuple, auto-resolve a policy the host can already satisfy, execute the pending effect, and pick a fallback reply when the model produced nothing deliverable. This module owns that protocol so the host only implements delivery.

The only required callback is deliver_reply/3. Everything else has a protocol-level default:

• {:reply, result} — deliver_reply/3 with the reply text, or fallback_reply/2 → no_response/2 when the text is empty
• {:no_response, result} — no_response/2
• {:awaiting, awaitable, result} — satisfied_resolution/2 first; a resolution re-enters Spectre.Turn.resolve_policy/3 and the loop continues with the new decision. :not_satisfied delivers the policy request via policy_request/3.
• {:needs, effect, result} — execute?/3 (default true) then Spectre.execute/3; the executed result re-enters the loop. A false veto delivers through suppressed/3.
• {:completed, completion, result} — action_result/3

Example

defmodule MyApp.ChatDelivery do
  @behaviour Spectre.Turn.Dispatcher

  @impl true
  def deliver_reply(text, _result, opts) do
    MyApp.Chat.send(Keyword.fetch!(opts, :conversation_id), text)
  end
end

{:ok, turn} = Spectre.turn(instance, message.text, opts)
{:ok, _delivered} = Spectre.Turn.Dispatcher.dispatch(turn, MyApp.ChatDelivery)

The loop is bounded: a turn crossing more than 4 policy-resolution or execution steps returns {:error, {:dispatch_loop_exceeded, decision}} instead of spinning.