Inflight-lease bookkeeping shared by Rheo.Group and Rheo.Producer.

An inflight set maps an opaque key (a task monitor reference for the Group, a lease_id for the Producer) to a metadata map that always contains :lease. All functions are pure; the owning process performs backend calls and telemetry around them.

Examples

iex> event = %Rheo.Event{id: "e1", stream: "s", partition: 0, sequence: 1,
...>   timestamp: ~U[2026-01-01 00:00:00.000Z], payload: %{}}
iex> lease = %Rheo.Lease{lease_id: "l1", stream: "s", group: "g", event_id: "e1",
...>   event: event, consumer_id: "c", attempt: 1,
...>   leased_at: ~U[2026-01-01 00:00:00.000Z], expires_at: ~U[2026-01-01 00:00:30.000Z]}
iex> inflight = Rheo.Inflight.put(Rheo.Inflight.new(), "l1", lease)
iex> {Rheo.Inflight.size(inflight), Rheo.Inflight.capacity(inflight, 10)}
{1, 9}
iex> {:ok, %{lease: ^lease}, inflight} = Rheo.Inflight.pop(inflight, "l1")
iex> Rheo.Inflight.size(inflight)
0