i3 autostart: open the dashboard fullscreen on the primary output

No keyboard needed after a reboot, and a second connected display can no
longer capture the window.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

install.sh

@@ -194,7 +194,12 @@ if [ "$do_i3" = yes ]; then
 # Exactly ONE gesture daemon: lisgd does not grab the device exclusively, so a
 # second instance makes every swipe fire twice.
 exec --no-startup-id $BIN/socktop-gestures
-exec --no-startup-id \$TERMINAL -e $BIN/socktop-rack
+# Start the dashboard on the primary output and fullscreen (which also hides
+# the i3 bar), so no keyboard is needed after a reboot and a second monitor
+# cannot capture it. --class gives the window a distinct instance name for the
+# rule; alacritty syntax -- adapt for other terminals.
+for_window [instance="^socktop-rack\$"] move window to output primary, fullscreen enable
+exec --no-startup-id \$TERMINAL --class socktop-rack -e $BIN/socktop-rack
 EOF
 		if i3 -C -c "$i3conf" >/dev/null 2>&1; then
 			echo "==> added i3 autostart (backup: $bak)"