Tools: one toolbar button for all tools, styled tool windows

- ToolBox: instead of a text button per tool (which did not fit the 60x60
  icon row and overlapped the icons) the HUD gets one "tools" icon button
  with a popup listing every visible tool, sorted by localized name.
- ToolWindow: chrome that follows the UI style guide (title on the left,
  close on the right, drag-to-move, double-click/maximize, edge resize),
  a status bar with buffered status/hint text, dirty-state confirmation
  and keyboard shortcuts (Ctrl+S in _Input, other keys only when no
  focused control consumed them).
- ToolTheme: denser copy of the game theme for editor toolbars;
  ToolStatusKind: status bar message kinds.
- New tools icon and the tool window texts (unsaved changes, maximize,
  close, menu title) in en/ru.

src/Tool/ToolTheme.cs

@@ -0,0 +1,53 @@
+using Cthangover.Core.UI.Theming;
+using Godot;
+
+namespace Cthangover.Mods.Interface.Tool
+{
+    /// <summary>
+    /// Dense variant of <see cref="CthangoverTheme"/> for developer tool windows.
+    /// The game theme is tuned for player panels (buttons padded 18×11, inputs
+    /// 12×9), which makes an editor toolbar of ten controls overflow even a
+    /// full-HD window. This theme keeps every colour, radius and type variation
+    /// of the shared theme — the style guide still holds — and only tightens
+    /// the content margins of the boxes, so tools fit more controls without a
+    /// second palette. Built once by copying the shared theme and replacing its
+    /// flat boxes with tightened duplicates; the shared theme is never mutated.
+    /// </summary>
+    public static class ToolTheme
+    {
+        private const int MaxVerticalMargin = 5;
+        private const int MaxHorizontalMargin = 10;
+
+        private static Theme instance;
+
+        /// <summary>Shared dense theme instance, built lazily from the game theme.</summary>
+        public static Theme Get() => instance ??= Build();
+
+        private static Theme Build()
+        {
+            var theme = (Theme)CthangoverTheme.Get().Duplicate();
+            theme.DefaultFontSize = UiTokens.FontBody;
+
+            foreach (var type in theme.GetTypeList())
+            {
+                foreach (var name in theme.GetStyleboxList(type))
+                {
+                    if (theme.GetStylebox(name, type) is not StyleBoxFlat flat)
+                        continue;
+
+                    var dense = (StyleBoxFlat)flat.Duplicate();
+                    dense.ContentMarginTop = Mathf.Min(dense.ContentMarginTop, MaxVerticalMargin);
+                    dense.ContentMarginBottom = Mathf.Min(dense.ContentMarginBottom, MaxVerticalMargin);
+                    dense.ContentMarginLeft = Mathf.Min(dense.ContentMarginLeft, MaxHorizontalMargin);
+                    dense.ContentMarginRight = Mathf.Min(dense.ContentMarginRight, MaxHorizontalMargin);
+                    theme.SetStylebox(name, type, dense);
+                }
+
+                if (theme.HasFontSize("font_size", type) && theme.GetFontSize("font_size", type) > UiTokens.FontBody)
+                    theme.SetFontSize("font_size", type, UiTokens.FontBody);
+            }
+
+            return theme;
+        }
+    }
+}