Route context-menu captures through chrome.downloads so they resolve
Chrome's real filename (Content-Disposition, extension, etc.) via the
same onDeterminingFilename path auto-capture already uses, and harden
the native host against the bare-directory destDir KGet was misparsing
as a filename.
Chrome's own "Ask where to save each file" setting shows a native
picker before the extension can ever intercept the download, and no
extension API can read or suppress it -- surface this clearly in
install.sh, the README, and a popup shortcut instead of leaving it
buried as a footnote.
Also fixes silently missing "download complete" notifications: KGet
only fires its own finished-notification if a transfer was observed
in a non-finished state at least once, so small/fast downloads that
complete before that first observation never get one. The native
host now drives its own notification via notify-send, polling actual
transfer progress instead of relying on KGet's internal check, and
install.sh disables KGet's own notification to avoid duplicates.
Switch auto-capture from onCreated to onDeterminingFilename, which
fires once Chrome has already resolved the real filename (from
Content-Disposition or the URL). That name is now passed through to
the native host and used to build a full dir+filename destination for
addTransfer, replacing showNewTransferDialog. A non-empty destDir
makes KGet skip its interactive dialog and start immediately, which
also fixes it showing an opaque URL path segment as the filename for
signed/obfuscated URLs (e.g. cloud storage links) instead of the real
name.
Also enable KGet's existing (but disabled-by-default) "Download
Finished" KNotify popup via install.sh, so there's still feedback now
that captures no longer show an interactive dialog.
andwati