refactor: keep the word cloud shape tap as a stable member callback

[g1f9]

🤔 This is a ...

• Refactoring

🔗 Related issue link

Follow-up to #4679 (fix #4649).

🔗 Related PR link

#4679

🐞 Bugserver case id

💡 Background and solution

#4679 landed the word cloud shape tap lifecycle fix, but it kept a { stage, fn } record on the series so that release() could still reach the stage after the fact:

protected _afterWordcloudShapeDrawTap?: { stage: IStage; fn: () => void };

That record is unnecessary. hooks.afterRender is declared as SyncHook<[IStage]>, so a tap already receives the stage it runs on — the same signature Stage uses for its own constructor tap (this.afterRender = stage => { ... }).

So the callback can simply be a member with a stable identity:

const AFTER_WORDCLOUD_SHAPE_DRAW_TAP = 'afterWordcloudShapeDraw';

protected _afterWordcloudShapeDraw = (stage: IStage) => {
  stage.hooks.afterRender.unTap(AFTER_WORDCLOUD_SHAPE_DRAW_TAP, this._afterWordcloudShapeDraw);

  const globalInstance = this._option?.globalInstance;
  if (!globalInstance) {
    return;
  }
  this._option.dispatchEvent?.(ChartEvent.afterWordcloudShapeDraw, { instance: globalInstance });
  globalInstance.getChart().getOption().performanceHook?.afterWordcloudShapeDraw?.(globalInstance);
};

The three places that need a stage each already have one:

where	stage comes from
the tap unregistering itself	the stage argument the hook passes in
re-registering after a new layout	the local stage already resolved in onLayoutFinished
release()	this._option?.globalInstance?.getStage() — _option is only cleared by super.release(), which runs after

A stable member identity is also exactly what unTap(name, fn) wants, so the fn argument requested in the #4679 review is preserved: a stage hosting more than one word cloud series still only drops its own callback.

This deletes the _afterWordcloudShapeDrawTap field and the _removeAfterWordcloudShapeDrawTap helper, and moves the tap name into one module constant so registration and removal cannot drift apart.

📝 Changelog

Internal refactor, no behavior change — no changelog entry ("type": "none").

Language	Changelog
🇺🇸 English
🇨🇳 Chinese

☑️ Self-Check before Merge

• Doc is updated/provided or not needed
• Demo is updated/provided or not needed
• TypeScript definition is updated/provided or not needed
• Changelog is provided or not needed

Verified: word-cloud-shape-release.test.ts (removal on release, no duplicate registration) and the two background cases in update-spec.test.ts all pass; tsc --noEmit clean; prettier clean.