Add link understanding tool support (#1637)

* Add

* Fix

---------

Co-authored-by: Richard <dasilva333@DESKTOP-74E3GJO.localdomain>

src/link-understanding/format.ts

@@ -0,0 +1,10 @@
+export function formatLinkUnderstandingBody(params: { body?: string; outputs: string[] }): string {
+  const outputs = params.outputs.map((output) => output.trim()).filter(Boolean);
+  if (outputs.length === 0) {
+    return params.body ?? "";
+  }
+
+  const base = (params.body ?? "").trim();
+  if (!base) return outputs.join("\n");
+  return `${base}\n\n${outputs.join("\n")}`;
+}