fix(mumble): Persist data

modules/home/emacs.nix

@@ -8,6 +8,7 @@ in {
       description = ''
         The path to the Emacs user directory.
       '';
+      # Mutable config.
       default = "/persist/dots/modules/home/users/msyds/emacs";
       type = lib.types.path;
     };

modules/home/users/crumb/mumble.nix

@@ -8,11 +8,21 @@ in {
 
   config = lib.mkIf cfg.enable {
     sydnix.impermanence.directories =
-      let xdg-config-home =
-        lib.removePrefix "${config.home.homeDirectory}"
-          (lib.removePrefix "~"
-            (config.xdg.configHome));
-      in [ "${xdg-config-home}/Mumble" ];
+      let
+        xdg-config-home =
+          lib.removePrefix "${config.home.homeDirectory}"
+            (lib.removePrefix "~"
+              (config.xdg.configHome));
+        xdg-data-home =
+          lib.removePrefix "${config.home.homeDirectory}"
+            (lib.removePrefix "~"
+              (config.xdg.dataHome));
+      in [
+        # Mutable config.
+        "${xdg-config-home}/Mumble"
+        # Persist Mumble's database, plugins, themes, etc.
+        "${xdg-data-home}/Mumble"
+      ];
 
     home.packages = [ pkgs.mumble ];
   };