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.
install.sh now sets KGet's remembered "New Download" folder
(kgetrc Internal/LastDirectory) to the XDG downloads directory if it
isn't already configured, since KGet's own out-of-the-box default was
Documents. Falls back correctly even when xdg-user-dir has no
user-dirs.dirs config to read (it silently returns bare $HOME
otherwise).
Also add a GitHub Actions workflow that packages extension/ into a zip
and publishes a GitHub Release with generated notes whenever a
v*.*.* tag is pushed.