fix(embed): default iframe color-scheme to light when no theme set

Changes the fallback from 'light dark' to 'light' to match the inner document's default behavior, which always defaults to light when no theme is specified.

Author: amdevz

frontend/apps/remark42/app/utils/create-iframe.ts

@@ -20,7 +20,7 @@ export function createIframe({ __colors__, styles, ...params }: Params) {
     padding: 0,
     margin: 0,
     overflow: 'hidden',
-    colorScheme: params.theme === 'dark' ? 'dark' : params.theme === 'light' ? 'light' : 'light dark',
+    colorScheme: params.theme === 'dark' ? 'dark' : 'light',
     ...styles,
   });