Add Frametop Remote Access, a settings app for the VNC view

A GTK 4 / libadwaita app (remote/ft-remote-settings, on the host's own
Python like the gaze probe): remote access on and off (REMOTE, applied at
once when the desktop allows it), the tailnet name and address to connect
to, and the VNC password shown, copied, or replaced. The password stays
random and made on the Frame, in ~/.config/frametop-remote; none is in
the code.

session/remote-ctl.sh starts, stops, and reports remote access; the
session uses it and leaves a remote-capable marker, since KWin allows the
capture only in a desktop that started with REMOTE=1. The password
between krdp and the VNC bridge (local only, but on krdp's command line)
is now new at every start. The installer adds the app to the menu.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

install.sh

@@ -78,6 +78,7 @@ step "7/9 multi-screen desktop (ft-screens), Frametop Input Settings, and Framet
 "$root/desktops.sh" install >/dev/null
 "$root/input-settings/install.sh"
 "$root/display-settings/install.sh"
+"$root/remote/install.sh"
 on_frame "sed -i 's/^POINTER=0/POINTER=1/' ~/.config/frametop.conf; grep -q '^POINTER=' ~/.config/frametop.conf || echo 'POINTER=1' >> ~/.config/frametop.conf"
 echo "the launcher's Desktop entry now opens the multi-screen desktop; 3D mouse on (POINTER=1 in ~/.config/frametop.conf)"