web-player: extract menu, paged list and play-all components from pages

web-player/src/lib/state/menu.svelte.ts

@@ -0,0 +1,22 @@
+import { contextMenuPosition, type MenuPosition } from '$lib/utils/menuPosition';
+
+export type MenuState<T> = { target: T } & MenuPosition;
+
+export function createMenu<T>() {
+	let state = $state<MenuState<T> | null>(null);
+
+	return {
+		get state() {
+			return state;
+		},
+		open(event: MouseEvent, target: T) {
+			event.preventDefault();
+			state = { target, ...contextMenuPosition(event) };
+		},
+		close() {
+			state = null;
+		}
+	};
+}
+
+export type Menu<T> = ReturnType<typeof createMenu<T>>;