feat(media): add mpv and imv media viewers

new `modules/media.nix`: mpv (with mpv-gallery-view) for video/audio, imv for
images. imv key binds run per-file actions — copy path via `wl-copy`, rotate/
flip via `magick`, delete, open in gimp, show `mediainfo`. wallpaper via awww
plus a `setbg` wrapper (symlink to ~/.local/share/bg + live push); awww-daemon
and boot restore wired as hyprland exec-once. add mako as the notification
daemon backing the notify-send toasts.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

modules/home.nix

@@ -11,7 +11,7 @@ let
   editor = "nvim";
 in
 {
-  imports = [ ./gpg.nix ];
+  imports = [ ./gpg.nix ./media.nix ];
 
   home.sessionVariables = {
     TERMINAL = terminal;
@@ -332,10 +332,27 @@ in
         # Uses foot's default socket, which footclient also defaults to.
         # Tradeoff: if the server dies, all foot windows die with it.
         "foot --server"
+        # wallpaper (see modules/media.nix): start the awww daemon, then restore
+        # the persisted choice. awww keeps no state across restarts, so re-push
+        # the ~/.local/share/bg symlink if it exists.
+        "awww-daemon"
+        "sh -c '[ -e \"$HOME/.local/share/bg\" ] && awww img \"$HOME/.local/share/bg\"'"
       ];
     };
   };
 
+  # Notification daemon. notify-send clients (e.g. imv's info/delete toasts in
+  # modules/media.nix, gpg-agent errors) need a running server on the bus.
+  # Minimal to match the desktop: Nerd Font, no rounding, square border.
+  services.mako = {
+    enable = true;
+    settings = {
+      font = "JetBrainsMono Nerd Font 10";
+      border-radius = 0;
+      default-timeout = 5000;
+    };
+  };
+
   programs.waybar = {
     enable = true;
     settings = {