fix(frontend): resolve /mnt/ links in markdown to artifact API URLs (#2243)

* fix(gateway): forward agent_name and is_bootstrap from context to configurable

The frontend sends agent_name and is_bootstrap via the context field
in run requests, but services.py only forwards a hardcoded whitelist
of keys (_CONTEXT_CONFIGURABLE_KEYS) into the agent's configurable
dict.  Since agent_name was missing, custom agents never received
their name — make_lead_agent always fell back to the default lead
agent, skipping SOUL.md, per-agent config and skill filtering.

Similarly, is_bootstrap was dropped, so the bootstrap creation flow
could never activate the setup_agent tool path.

Add both keys to the whitelist so they reach make_lead_agent.

Fixes #2222

* fix(frontend): resolve /mnt/ links in markdown to artifact API URLs

AI agent messages contain links like /mnt/user-data/outputs/file.pdf
which were rendered as-is in the browser, resulting in 404 errors.
Images already got the correct treatment via MessageImage and
resolveArtifactURL, but anchor tags (<a>) were passed through
unchanged.

Add an 'a' component override in MessageContent_ that rewrites
/mnt/-prefixed hrefs to the artifact API endpoint, matching the
existing image handling pattern.

Fixes #2232

---------

Co-authored-by: JasonOA888 <JasonOA888@users.noreply.github.com>
Co-authored-by: Willem Jiang <willem.jiang@gmail.com>

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

@@ -1,6 +1,6 @@
 import type { Message } from "@langchain/langgraph-sdk";
 import { FileIcon, Loader2Icon } from "lucide-react";
-import { memo, useMemo, type ImgHTMLAttributes } from "react";
+import { memo, useMemo, type AnchorHTMLAttributes, type ImgHTMLAttributes } from "react";
 import rehypeKatex from "rehype-katex";
 
 import { Loader } from "@/components/ai-elements/loader";
@@ -127,6 +127,13 @@ function MessageContent_({
       img: (props: ImgHTMLAttributes<HTMLImageElement>) => (
         <MessageImage {...props} threadId={threadId} maxWidth="90%" />
       ),
+      a: ({ href, ...props }: AnchorHTMLAttributes<HTMLAnchorElement>) => {
+        if (href && href.startsWith("/mnt/")) {
+          const url = resolveArtifactURL(href, threadId);
+          return <a {...props} href={url} target="_blank" rel="noopener noreferrer" />;
+        }
+        return <a {...props} href={href} />;
+      },
     }),
     [threadId],
   );