TunaKit 1.13.0

• Breaking: catalogs are now two sibling kinds. Catalog vends objects and
  is a source: it feeds subject and target search, carries a search priority,
  and is listed in Sources. The new ActionCatalog vends
  actions: [CatalogAction] and is none of those things. It is not a refinement
  of Catalog, so a catalog that mixes items and actions can no longer be
  written. See ADR 0006.

• Breaking: ExtensionDeclaration gains actionCatalogs: [ActionCatalogDeclaration].
  Action catalogs must be declared there, never in catalogs. catalogs now
  defaults to [], so an extension may contribute only actions. Both kinds share
  one identifier namespace.

• Breaking: appActionEnrichments and defaultActionRankings must reference
  action catalogs. Naming a source catalog is a declaration error.

• Breaking: app action enrichment is purely additive. Naming an action
  catalog for an app no longer removes it from anywhere else — it only orders it
  for that app. Where an action applies is decided solely by
  supportedSubjectTypes and subjectPredicate. Extensions that mirrored their
  actions through a search catalog to work around the old behavior should delete
  the mirroring.

• Action catalogs have no scan lifecycle: no scan(), no reportScanFinished(),
  no retained-state release. They are built from an ActionCatalogDefinition,
  which carries only an identifier and a name — no enablement, advanced flag, or
  settings. A setting that configures a verb belongs in the extension's own
  settings.

• Added ActionAvailabilityProviding, for an action that cannot run under
  current conditions — its app is not installed, a permission was refused, it has
  nothing to operate on. Unavailable actions are filtered wherever actions are
  matched to a subject. This replaces the scan-to-empty signal that action
  catalogs no longer have. It is read during search, so keep it cheap.

• Added MainWindow.playTransition(_:duration:animations:finalState:completion:)
  and MainWindow.AnimationDirection. Themes that need their own show/hide
  animations can now add them to the content layer while TunaKit keeps owning
  the transition lifecycle: superseding an in-flight transition, the
  animationsEnabled bypass, and ordering the window out after a hide.
  playShowAnimations and playHideAnimations are wrappers over it and keep
  their signatures; playHideAnimations now orders the window out itself when
  the hide completes, so themes no longer have to.