fix(messages): prevent URL autolink bleeding into adjacent text

For human messages, disable remark-gfm autolink feature to prevent
URLs from incorrectly including adjacent text (especially Chinese
characters) as part of the link. This ensures that when users input
"https://example.com 帮我分析", only the URL becomes a link.

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/components/workspace/messages/message-list-item.tsx

@@ -30,7 +30,7 @@ import {
   type UploadedFile,
 } from "@/core/messages/utils";
 import { useRehypeSplitWordsIntoSpans } from "@/core/rehype";
-import { streamdownPlugins } from "@/core/streamdown";
+import { humanMessagePlugins, streamdownPlugins } from "@/core/streamdown";
 import { cn } from "@/lib/utils";
 
 import { CopyButton } from "../copy-button";
@@ -222,10 +222,11 @@ function MessageContent_({
   }), [citationMap, thread_id, isHuman]);
 
   // Render message response
+  // Human messages use humanMessagePlugins (no autolink) to prevent URL bleeding into adjacent text
   const messageResponse = cleanContent ? (
     <AIElementMessageResponse
-      remarkPlugins={streamdownPlugins.remarkPlugins}
-      rehypePlugins={isHuman ? streamdownPlugins.rehypePlugins : [...rehypePlugins, [rehypeKatex, { output: "html" }]]}
+      remarkPlugins={isHuman ? humanMessagePlugins.remarkPlugins : streamdownPlugins.remarkPlugins}
+      rehypePlugins={isHuman ? humanMessagePlugins.rehypePlugins : [...rehypePlugins, [rehypeKatex, { output: "html" }]]}
       components={markdownComponents}
     >
       {cleanContent}

frontend/src/core/streamdown/plugins.ts

@@ -12,3 +12,15 @@ export const streamdownPlugins = {
     [rehypeKatex, { output: "html" }],
   ] as StreamdownProps["rehypePlugins"],
 };
+
+// Plugins for human messages - no autolink to prevent URL bleeding into adjacent text
+export const humanMessagePlugins = {
+  remarkPlugins: [
+    // Use remark-gfm without autolink literals by not including it
+    // Only include math support for human messages
+    [remarkMath, { singleDollarTextMath: true }],
+  ] as StreamdownProps["remarkPlugins"],
+  rehypePlugins: [
+    [rehypeKatex, { output: "html" }],
+  ] as StreamdownProps["rehypePlugins"],
+};