the probe title field is documented as an httpx-style page title, but
extractTitle returned the raw regex capture, so a title like
"Tom & Jerry" was reported verbatim instead of "Tom & Jerry".
run it through html.UnescapeString before trimming so the reported
title matches the rendered page.
adds an httpx-style -probe scanner reporting liveness, final status, page
title, server header and the redirect chain, plus -sarif/-markdown export
flags that serialize the collected run after the scan loop. the report
serializers live in a decoupled internal/report package consuming a raw-json
result model so they never import scan types.
