v0.13.0

Changed (breaking)

• SelectorSpec is now keyword-only and requires a kind: SelectorKind field
  (SelectorKind.LIST or SelectorKind.RETRIEVE). The kind tells the
  dispatcher whether to materialize the selector return as a list or as a
  single retrieve-shaped instance, and it is cross-checked against the
  mount point at as_view() time — a LIST spec on SelectorRetrieveView
  (or the "retrieve" action_specs entry) raises ImproperlyConfigured
  fail-fast. Making the kind explicit lets a spec be reused outside an HTTP
  request (management command, cron job, non-DRF caller) without the
  semantics living implicitly in the call site.
• ServiceSpec's output pipeline is collapsed into a single nested field:
  output_selector_spec: SelectorSpec | None. The previous flat fields
  output_selector, output_serializer, output_serializer_context,
  select_related, prefetch_related, annotations, and
  extend_queryset are removed; they now live on the nested spec (whose
  kind must be SelectorKind.RETRIEVE). The mutation dispatch path
  validates and consumes the nested spec, and ActionSerializerResolver
  reads the response serializer from output_selector_spec.output_serializer.
• OutputSelector Protocol removed. The "post-mutation re-fetch" selector
  is now structurally a RetrieveSelector (nested under
  ServiceSpec.output_selector_spec) and the result kwarg, when needed,
  is declared directly on the user's function signature.
• @selector_action's detail= parameter is removed. The DRF URL shape
  is pinned from spec.kind (LIST → detail=False, RETRIEVE → detail=True) — there is no longer a way to override it. If you need a
  URL shape that doesn't match the response shape (a detail action that
  returns a list, or a collection action that returns a single resource),
  fall back to DRF's plain @action and write the dispatch yourself.
  @service_action still takes detail= (mutation routing is decoupled
  from the read-shape distinction).
• The internal dispatch_retrieve_selector helper is folded into
  dispatch_selector_for_spec, which now branches on spec.kind. Callers
  outside the library should not be affected (the helpers live under
  selectors/utils.py and were never part of the public API), but the
  symbol no longer exists.