Tray: About window, fixed-width device table with totals; WTFPL

Add an About window (client and agent details, protocol versions), pin the
device table's column widths and add a total row, show the version in the
header and drop the refresh button. Relicense under WTFPL.

Co-Authored-By: Claude <noreply@anthropic.com>

dist/arch/build-pkg.sh

@@ -69,8 +69,7 @@ builddate = $(date +%s)
 packager = AB <ab@hexor.cy>
 size = ${size}
 arch = ${arch}
-${relations}license = MIT
-license = Apache
+${relations}license = WTFPL
 PKGINFO
 
 # Scriptlet: create the dedicated system user the service runs as, keep systemd