* xftp-server: embed file download widget in XFTP server web page
When a URL has a hash fragment (>50 chars), the server page shows the
file download UI instead of the server info page. Embeds xftp-web
assets (JS, CSS, crypto worker) and protocol overlay with matching
website content. Overlay renders below the server navbar.
* xftp-server: fix overlay scroll lock, remove extra margin, fix dark SVG
* xftp-server: move file transfer widget to standalone /file page
* web: collapse all repeated Nothing sections in render
section_ only collapsed the first occurrence of a section when content
was Nothing, leaving subsequent sections with the same label intact.
This caused SMP server pages to show raw <x-xftpConfig> tags.
* xftp-server: update bundled css/js
* xftp-server: move file.html to xftp-server, rename xftp bundle dir
* web: remove unused server-info wrapper div
* refactor
* fix
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Co-authored-by: Evgeny <evgeny@poberezkin.com>
