website: the share card shows the product, not just the words

The operator went to post the link and found the card out of date: it was the
2026-07-18 design - a headline and two lines of text on a dark field, nothing of
the product, and older than everything the site has become since.

- og-image.png and og-image-en.png rebuilt around the laptop, with the hero's
  own poster frame on its screen.
- scripts/make_og_card.py: the headline, logo and button are lifted as PIXELS
  from the previous card and composited with `lighter` onto flat --bg-0, because
  the site's font is a woff2 and nothing here can draw a glyph with it. A new
  headline therefore CANNOT be made with this script - new words go back to the
  design tool and this takes that card as its source. The lede lines are gone;
  the laptop says what they said.
- ?v=2 on every og:image and twitter:image (20 pages): a scraper caches by URL,
  so a new picture at the old URL would reach nobody. A card already attached to
  a post still does not change - that post must drop the preview and re-add the
  link after a re-scrape.

website/en/testing.html

@@ -17,14 +17,14 @@
     <meta property="og:url" content="https://felhom.eu/en/testing">
     <meta property="og:title" content="Looking for testers — your own cloud at home, free during the test">
     <meta property="og:description" content="Your photos and documents on your own machine, at home. I do the setup and pay for the domain for two years. Up to 5 households.">
-    <meta property="og:image" content="https://felhom.eu/assets/og-image.png">
+    <meta property="og:image" content="https://felhom.eu/assets/og-image.png?v=2">
     <meta property="og:locale" content="en_GB">
     <meta property="og:site_name" content="Felhom.eu">
 
     <meta name="twitter:card" content="summary_large_image">
     <meta name="twitter:title" content="Looking for testers — your own cloud at home">
     <meta name="twitter:description" content="No fee during the test. I do the setup and pay for the domain for two years.">
-    <meta name="twitter:image" content="https://felhom.eu/assets/og-image.png">
+    <meta name="twitter:image" content="https://felhom.eu/assets/og-image.png?v=2">
 
     <script type="application/ld+json">
     {