add default config for japanese input

modules/gnome.nix

@@ -102,6 +102,21 @@ in
     };
   };
 
+  # IBus Mozc (Japanese) configuration - default to Hiragana input mode
+  home.file.".config/mozc/ibus_config.textproto".text = ''
+    engines {
+      name : "mozc-jp"
+      longname : "Mozc"
+      layout : "default"
+      layout_variant : ""
+      layout_option : ""
+      rank : 80
+      symbol : "あ"
+      composition_mode : HIRAGANA
+    }
+    active_on_launch: True
+  '';
+
   # Configure cursor theme system-wide
   home.pointerCursor = {
     name = "Adwaita";