A JSON template (product.json) broke after I edited it. Can you rebuild it?

Yes. Online Store 2.0 templates such as templates/product.json are JSON files that list which sections and blocks render. A hand edit can leave a bad section key, an orphaned block reference, or invalid JSON, and the page then fails to render. We rebuild the template tree, valid JSON, every section key matching a real section file, blocks in the right order, so the page loads as expected again.