An HTML script src or base href with percent-encoded letters or
surrounding whitespace was looked up literally, so an inventoried script
was reported as not-found. Apply HTML attribute and URL parser
whitespace handling, then percent-decode the path as the URL standard
does. Encoded dot and separator bytes are still rejected, and paths that
decode to NUL or non-UTF-8 bytes are rejected explicitly.
Closes#1236
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>