sway/xdg-desktop-portals: fix moby so app chooser is provided by gnome portal, even as the requirements for camera access are provided by gtk

hosts/common/programs/sway/default.nix

@@ -208,7 +208,9 @@ in
       # - org.freedesktop.impl.portal.Settings (@settings_iface@)
       # - org.freedesktop.impl.portal.Wallpaper (@wallpaper_iface@)
       "xdg-desktop-portal-gtk"
-      # xdg-desktop-portal-wlr provides portals for screenshots/screen sharing
+      # xdg-desktop-portal-wlr provides portals for:
+      # - org.freedesktop.impl.portal.ScreenCast
+      # - org.freedesktop.impl.portal.Screenshot
       "xdg-desktop-portal-wlr"
       "xdg-terminal-exec"  # used by sway config
     ] ++ [
@@ -244,12 +246,22 @@ in
 
     fs.".config/xdg-desktop-portal/sway-portals.conf".symlink.text = ''
       # portals.conf docs: <https://flatpak.github.io/xdg-desktop-portal/docs/portals.conf.html>
-      # XXX(2024-11-28): `gnome` provides a more mobile-friendly file chooser than `gtk`,
+      #
-      #   only `gtk` provides Snapshot camera app with a permission's popup that allows me to grant it camera access.
+      # $interface=<impl list>
-      #   TODO: switch back to `wlr;gnome;gtk` ordering (or even `wlr;gnome`), but remove from `gnome` whatever boken portal is involved with that camera access.
+      # impl_list=(gtk|gnome|wlr|*|none)
+      #   where `none` means "don't provide an impl for this interface"
+      #   where `*` means use the first impl found, in lexicographic order
+      #
+      # special interface name `default` is used as a catchall for any interface not listed explicitly
       [preferred]
-      default=wlr;gtk
+      default=wlr;gtk;gnome
-      # default=wlr;gnome;gtk
+
+      # Access portal: "An application wants to [...] Deny Access  /  Grant Access"
+      # XXX(2024-12-04): gnome Access portal simply doesn't render on non-Gnome DEs
+      org.freedesktop.impl.portal.Access=gtk
+      # XXX(2024-12-04): the gnome file-chooser (libadwaita) is much more mobile-friendly than the gtk ones
+      org.freedesktop.impl.portal.FileChooser=gnome
+
     '';
 
     fs.".config/sway/config".symlink.target = pkgs.substituteAll {