feat(UrlUtils): Resolve more URL formats

Resolves more formats of URLs correctly: absolute, root-relative, relative, parent-relative, and URLs with query strings and fragments.

src/util/UrlUtils.h

@@ -18,6 +18,13 @@ std::string ensureProtocol(const std::string& url);
  */
 std::string extractHost(const std::string& url);
 
+/**
+ * Extract hostname only from a URL (e.g., "example.com" from
+ * "http://example.com:8080/path"). Returns an empty string if no hostname can
+ * be determined.
+ */
+std::string extractHostname(const std::string& url);
+
 /**
  * Build full URL from server URL and path.
  * If path starts with /, it's an absolute path from the host root.