Kai v1.2.4

Fixed

• Updater dialog grew off-screen: long release notes now scroll inside a capped dialog (max-h-[85vh] + overflow-y-auto) instead of pushing the popup past the viewport.
• Release notes rendered as raw text: the updater dialog dumped bullets as plain text nodes, so **bold** and inline code showed literally. Notes now render as markdown via Streamdown (same pipeline as chat and markdown preview).