Fix plugin order: sanitize after parsing raw HTML

Move rehype-harden after rehypeRaw to ensure all HTML is sanitized.
Previously, harden ran before rehypeRaw, allowing unsanitized HTML
to be injected after the security check.

Author: kylecarbs

src/components/Messages/MarkdownCore.tsx

@@ -23,16 +23,16 @@ const REMARK_PLUGINS: Pluggable[] = [
 ];
 
 const REHYPE_PLUGINS: Pluggable[] = [
+  rehypeRaw, // Parse HTML elements first
   [
-    harden,
+    harden, // Sanitize after parsing raw HTML to prevent XSS
     {
       allowedImagePrefixes: ["*"],
       allowedLinkPrefixes: ["*"],
       defaultOrigin: undefined,
       allowDataImages: true,
     },
   ],
-  rehypeRaw, // Parse HTML elements
   [rehypeKatex, { errorColor: "var(--color-muted-foreground)" }], // Render math
 ];