Make page timestamps accessible to LLMs/crawlers but not visible on rendered pages

[alexakreizinger]

the ability to add timestamp metadata to pages is great, especially as a way to indicate content freshness to LLMs and other crawlers, but my team doesn't want to enable this feature as-is because we don't want the actual timestamp visible on rendered pages. it would be even better if we could "invisibly" add timestamp metadata to pages.

we did attempt a DIY fix by adding custom CSS to hide the timestamp, but unfortunately the timestamp element doesn't have a unique div ID, so that didn't work.