refactor(core): [CORE-20] type entry and converge initialization

packages/artplayer/src/icons/index.ts

@@ -1,10 +1,14 @@
 import { def, getIcon } from '../utils'
 import defaults from './defaults'
 
-export default class Icons {
+// eslint-disable-next-line ts/no-unsafe-declaration-merging -- The constructor defines a getter for every default key without class fields.
+interface Icons extends Record<keyof typeof defaults, HTMLElement> {}
+
+// eslint-disable-next-line ts/no-unsafe-declaration-merging -- The merged mapped interface describes the getters installed below.
+class Icons {
   readonly [key: string]: HTMLElement
 
-  constructor(art: { option: { icons: Record<string, string | HTMLElement> } }) {
+  constructor(art: { option: { icons: Readonly<Record<string, string | HTMLElement | undefined>> } }) {
     const icons: Record<string, string | HTMLElement | undefined> = { ...defaults, ...art.option.icons }
     for (const key in icons) {
       def(this, key, {
@@ -13,3 +17,5 @@ export default class Icons {
     }
   }
 }
+
+export default Icons