Add link understanding tool support (#1637)

* Add

* Fix

---------

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

src/link-understanding/detect.ts

@@ -0,0 +1,49 @@
+import { DEFAULT_MAX_LINKS } from "./defaults.js";
+
+// Remove markdown link syntax so only bare URLs are considered.
+const MARKDOWN_LINK_RE = /\[[^\]]*]\((https?:\/\/\S+?)\)/gi;
+const BARE_LINK_RE = /https?:\/\/\S+/gi;
+
+function stripMarkdownLinks(message: string): string {
+  return message.replace(MARKDOWN_LINK_RE, " ");
+}
+
+function resolveMaxLinks(value?: number): number {
+  if (typeof value === "number" && Number.isFinite(value) && value > 0) {
+    return Math.floor(value);
+  }
+  return DEFAULT_MAX_LINKS;
+}
+
+function isAllowedUrl(raw: string): boolean {
+  try {
+    const parsed = new URL(raw);
+    if (parsed.protocol !== "http:" && parsed.protocol !== "https:") return false;
+    if (parsed.hostname === "127.0.0.1") return false;
+    return true;
+  } catch {
+    return false;
+  }
+}
+
+export function extractLinksFromMessage(message: string, opts?: { maxLinks?: number }): string[] {
+  const source = message?.trim();
+  if (!source) return [];
+
+  const maxLinks = resolveMaxLinks(opts?.maxLinks);
+  const sanitized = stripMarkdownLinks(source);
+  const seen = new Set<string>();
+  const results: string[] = [];
+
+  for (const match of sanitized.matchAll(BARE_LINK_RE)) {
+    const raw = match[0]?.trim();
+    if (!raw) continue;
+    if (!isAllowedUrl(raw)) continue;
+    if (seen.has(raw)) continue;
+    seen.add(raw);
+    results.push(raw);
+    if (results.length >= maxLinks) break;
+  }
+
+  return results;
+}