URL parser

One text split, nothing more: scheme, userinfo, host, port, path, each query parameter, fragment, and origin. The split is hand-rolled RFC 3986 style rather than the browser URL constructor, so it works the same here, in the native app, and on odd inputs like a lone IPv6 host. Decoding is one strict pass per parameter, shown beside the raw text, and a parameter with a broken escape is flagged instead of silently mangling the whole table.