fix(vast): [PKG-VAST-03] preserve npm initialization with explicit workspace mode

packages/artplayer-plugin-vast/README.md

@@ -2,6 +2,32 @@
 
 VAST plugin for ArtPlayer
 
+## Initialization compatibility
+
+Existing npm calls keep creating the SDK player before the callback:
+
+```js
+artplayerPluginVast(({ imaPlayer, playUrl }) => {
+  imaPlayer.addEventListener('AdStarted', onAdStarted)
+  playButton.onclick = () => playUrl(adTagUrl)
+})
+```
+
+Code using the unpublished workspace 1.2 lazy initialization must select it explicitly:
+
+```js
+artplayerPluginVast((context) => {
+  context.playerOptions.autoResize = false
+  playButton.onclick = () => context.playUrl(adTagUrl)
+}, { compatibility: 'workspace-1.2' })
+```
+
+The callback may be asynchronous. Core destruction releases the ad session and prevents
+later requests or recreation. Explicit plugin `destroy()` allows a new ad session while
+the core is alive. See the architecture guide for mode-specific fields and defaults.
+Public TypeScript declarations for the second argument are still being reconciled in
+PKG-VAST-04; these are JavaScript usage examples, not completed declaration acceptance.
+
 ## Maintenance
 
 Implementation modules, lifecycle ownership, test commands and pending compatibility