Thanks - if I'm not mistaken, this needs nodebb-plugin-link-preview, which isn't on by default in fresh installs. Without it the link didn't show anywhere, which led to my initial frustration (it's probably documented and I missed it). The fix is merged and deployed: new forum posts no longer send a url and carry the link only as a Link attachment, like Lemmy's do. Posts that were already federated keep the old url.
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Thanks - if I'm not mistaken, this needs nodebb-plugin-link-preview, which isn't on by default in fresh installs. Without it the link didn't show anywhere, which led to my initial frustration (it's probably documented and I missed it). The fix is merged and deployed: new forum posts no longer send a url and carry the link only as a Link attachment, like Lemmy's do. Posts that were already federated keep the old url.