Make the second menu entry an action instead of a report

"Apply now" had nothing to do in the normal case. Enabling applies, the
watcher handles everything installed afterwards, and the settings and
applications screens apply on their way out - so pressing it answered
"already applied to 14 applications" and that was the whole interaction.

It is now "Re-apply everything": the state is taken back and written again
from scratch. That is the answer to the question the status block can raise
but nothing could act on - Steam showing as not patched after a client
update, an application that drifted, a flag file edited by hand.

Uninstalling an application used to leave the entry shadowing it behind, in
the user home where the package manager cannot see it, offering to start a
program that is gone. A plain apply only looks at what exists now, so the
watcher never noticed either. Those are removed on every apply now, not just
when rebuilding.

src/lib/apply.sh

@@ -110,6 +110,8 @@ mca_apply() {
 	[[ $CFG_AUTOSTART == yes ]] && mca_autostart_apply
 	[[ $CFG_SPOTIFY == yes ]] && mca_spotify_apply
 
+	mca_prune_orphans
+
 	if (( MCA_CHANGES )) && mca_have update-desktop-database; then
 		update-desktop-database "$MCA_APPDIR" 2>/dev/null || true
 	fi