feat(site): add util reference pipeline (#537)

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

packages/html/src/store/container-mixin.ts

@@ -9,6 +9,11 @@ export type ContainerMixin<Store extends PlayerStore> = <Class extends MediaElem
   BaseClass: Class
 ) => Class & PlayerConsumerConstructor<Store>;
 
+/**
+ * Create a mixin that consumes player context and auto-attaches media elements.
+ *
+ * @param context - Player context to consume from an ancestor provider.
+ */
 export function createContainerMixin<Store extends PlayerStore>(context: PlayerContext<Store>): ContainerMixin<Store> {
   return <Class extends MediaElementConstructor>(BaseClass: Class) => {
     class PlayerContainerElement extends BaseClass implements PlayerConsumer<Store>, MediaContainer {

packages/html/src/store/provider-mixin.ts

@@ -9,6 +9,12 @@ export type ProviderMixin<Store extends PlayerStore> = <Class extends MediaEleme
   BaseClass: Class
 ) => Class & PlayerProviderConstructor<Store>;
 
+/**
+ * Create a mixin that provides player context to descendant elements.
+ *
+ * @param context - Player context to provide to descendants.
+ * @param factory - Factory function that creates a store instance.
+ */
 export function createProviderMixin<Store extends PlayerStore>(
   context: PlayerContext<Store>,
   factory: () => Store