feat: add localized development frames for package covers

locale/ui_en.properties

@@ -266,3 +266,6 @@ tools/unsaved_discard_text = There are unsaved changes. Discard them?
 tools/window_maximize = Maximize / restore (double-click the title)
 tools/window_close = Close
 tools/menu_title = Tools
+
+# --- Development cover ---
+ui/cover/in_development = In development

locale/ui_es.properties

@@ -266,3 +266,6 @@ tools/unsaved_discard_text = Hay cambios sin guardar. ¿Descartarlos?
 tools/window_maximize = Maximizar / restaurar (doble clic en el título)
 tools/window_close = Cerrar
 tools/menu_title = Herramientas
+
+# --- Development cover ---
+ui/cover/in_development = En desarrollo

locale/ui_ja.properties

@@ -266,3 +266,6 @@ tools/unsaved_discard_text = 保存していない変更があります。破棄
 tools/window_maximize = 最大化 / 元に戻す（タイトルをダブルクリック）
 tools/window_close = 閉じる
 tools/menu_title = ツール
+
+# --- Development cover ---
+ui/cover/in_development = 開発中

locale/ui_ko.properties

@@ -266,3 +266,6 @@ tools/unsaved_discard_text = 저장하지 않은 변경이 있습니다. 버릴
 tools/window_maximize = 최대화 / 복원 (제목 더블클릭)
 tools/window_close = 닫기
 tools/menu_title = 도구
+
+# --- Development cover ---
+ui/cover/in_development = 개발 중

locale/ui_ru.properties

@@ -266,3 +266,6 @@ tools/unsaved_discard_text = Есть несохранённые изменен
 tools/window_maximize = Развернуть / восстановить (двойной клик по заголовку)
 tools/window_close = Закрыть
 tools/menu_title = Инструменты
+
+# --- Development cover ---
+ui/cover/in_development = В разработке

locale/ui_vi.properties

@@ -266,3 +266,6 @@ tools/unsaved_discard_text = Có thay đổi chưa lưu. Bỏ chúng?
 tools/window_maximize = Phóng to / khôi phục (nhấp đúp vào tiêu đề)
 tools/window_close = Đóng
 tools/menu_title = Công cụ
+
+# --- Development cover ---
+ui/cover/in_development = Đang phát triển

locale/ui_zh.properties

@@ -266,3 +266,6 @@ tools/unsaved_discard_text = 有未保存的更改。要放弃吗？
 tools/window_maximize = 最大化 / 还原（双击标题）
 tools/window_close = 关闭
 tools/menu_title = 工具
+
+# --- Development cover ---
+ui/cover/in_development = 开发中

scenes/ui/development_frame.tscn

@@ -0,0 +1,56 @@
+[gd_scene format=3]
+
+[ext_resource type="Texture2D" path="ui_images/development_frame.png" id="1_frame"]
+[ext_resource type="Texture2D" path="ui_images/development_plaque_blank.png" id="2_blank"]
+[ext_resource type="Script" path="res://mods/ui_base/src/Theming/DevelopmentFrame.cs" id="3_script"]
+
+[node name="DevelopmentFrame" type="TextureRect"]
+layout_mode = 1
+anchors_preset = 15
+anchor_right = 1.0
+anchor_bottom = 1.0
+grow_horizontal = 2
+grow_vertical = 2
+mouse_filter = 2
+texture = ExtResource("1_frame")
+expand_mode = 1
+stretch_mode = 0
+script = ExtResource("3_script")
+
+[node name="Plaque" type="Control" parent="."]
+layout_mode = 0
+offset_right = 1536.0
+offset_bottom = 1024.0
+mouse_filter = 2
+
+[node name="Backing" type="ColorRect" parent="Plaque"]
+layout_mode = 0
+offset_left = 440.0
+offset_top = 895.0
+offset_right = 1096.0
+offset_bottom = 1005.0
+mouse_filter = 2
+color = Color(0, 0, 0, 1)
+
+[node name="Blank" type="TextureRect" parent="Plaque"]
+layout_mode = 0
+offset_left = 440.0
+offset_top = 895.0
+offset_right = 1096.0
+offset_bottom = 1005.0
+mouse_filter = 2
+texture = ExtResource("2_blank")
+expand_mode = 1
+
+[node name="Caption" type="Label" parent="Plaque"]
+layout_mode = 0
+offset_left = 440.0
+offset_top = 895.0
+offset_right = 1096.0
+offset_bottom = 1005.0
+mouse_filter = 2
+theme_override_colors/font_color = Color(1, 0.9, 0, 1)
+theme_override_font_sizes/font_size = 72
+text = "ui/cover/in_development"
+horizontal_alignment = 1
+vertical_alignment = 1

src/Theming/DevelopmentFrame.cs

@@ -0,0 +1,43 @@
+using Godot;
+
+namespace Cthangover.Mods.Interface.Theming
+{
+    /// <summary>
+    /// Keeps the localized plaque in the artwork's coordinate system so the same
+    /// prefab fits both small gallery covers and large detail views.
+    /// </summary>
+    public partial class DevelopmentFrame : TextureRect
+    {
+        private Control _plaque;
+        private TextureRect _blank;
+        private AtlasTexture _blankTexture;
+
+        public override void _Ready()
+        {
+            _plaque = GetNode<Control>("Plaque");
+            _blank = _plaque.GetNode<TextureRect>("Blank");
+            // Only the generated blank plaque is used; the original frame keeps
+            // its border and transparent opening. Geometry comes from the prefab.
+            _blankTexture = new AtlasTexture { Atlas = _blank.Texture, Region = _blank.GetRect() };
+            _blank.Texture = _blankTexture;
+            Resized += FitPlaque;
+            FitPlaque();
+        }
+
+        public override void _ExitTree()
+        {
+            Resized -= FitPlaque;
+            if (_blankTexture != null)
+            {
+                _blank.Texture = null;
+                _blankTexture.Dispose();
+                _blankTexture = null;
+            }
+        }
+
+        private void FitPlaque()
+        {
+            _plaque.Scale = Size / Texture.GetSize();
+        }
+    }
+}

src/Theming/UiKit.cs

@@ -1,4 +1,6 @@
 using Cthangover.Core.Mods.Resolvers;
+using Cthangover.Core.Scenes;
+using Cthangover.Core.Utils;
 using Godot;
 using Cthangover.Core.UI.Theming;
 
@@ -26,6 +28,14 @@ namespace Cthangover.Mods.Interface.Theming
     /// </summary>
     public static class UiKit
     {
+        /// <summary>Creates a non-interactive cover overlay; its scene owns the generated art and layout.</summary>
+        public static Control DevelopmentFrame(string version)
+        {
+            var frame = (Control)TscnScenes.LoadAndBuild("scenes/ui/development_frame.tscn");
+            frame.Visible = VersionHelper.IsInDevelopment(version);
+            return frame;
+        }
+
         /// <summary>Rounded frame from tokens; pass transparent border to omit it.</summary>
         public static StyleBoxFlat Frame(int radius, Color background, Color? border = null, int borderWidth = 1)
         {

tests/DevelopmentFrameTests.cs

@@ -0,0 +1,32 @@
+namespace Cthangover.Mods.Interface.Theming.Tests
+{
+    using Cthangover.Core.Mods.Testing;
+    using Godot;
+
+    /// <summary>Checks the real shared prefab and decoded alpha, including the release version without an overlay.</summary>
+    public class DevelopmentFrameTests
+    {
+        [ModTest("covers/development_frame")]
+        static void DevelopmentFrame(ModTestContext ctx)
+        {
+            var frame = UiKit.DevelopmentFrame("0.1.0");
+            var release = UiKit.DevelopmentFrame("1.0.0");
+            try
+            {
+                ModAssert.True(frame.Visible, "zero major is marked");
+                ModAssert.False(release.Visible, "released package is unmarked");
+                ModAssert.Equal((int)Control.MouseFilterEnum.Ignore, (int)frame.MouseFilter, "frame does not intercept cover clicks");
+                var texture = ((TextureRect)frame).Texture;
+                ModAssert.True(texture != null, "generated texture resolves through the mod provider");
+                using var image = texture.GetImage();
+                ModAssert.True(image.GetPixel(image.GetWidth() / 2, image.GetHeight() / 2).A == 0, "centre leaves the game art visible");
+                ModAssert.True(image.GetPixel(image.GetWidth() / 2, 4).A > 0.9f, "hazard tape is visible");
+            }
+            finally
+            {
+                frame.Free();
+                release.Free();
+            }
+        }
+    }
+}