CVE-2026-108260: @tinacms/web-components: `tina-markdown` writes rich-text link URLs into `href` without scheme validation, allowing stored XSS

<tina-markdown> renders a rich-text AST into the DOM and, for a nodes, assigns the node’s URL straight to the anchor’s href with no scheme check. A link authored in the CMS as javascript:… renders as a live javascript: anchor, so a visitor who clicks it executes attacker-supplied script in the site’s origin. Every sibling renderer in the repository already sanitizes these URLs; this one does not.