Hide ImGui compat factories behind legacy XCUI interop

new_editor/src/XCUIBackend/XCUIEditorFontSetup.cpp

@@ -12,8 +12,6 @@ constexpr float kUiFontSize = 18.0f;
 constexpr const char* kPrimaryUiFontPath = "C:/Windows/Fonts/segoeui.ttf";
 constexpr const char* kChineseFallbackFontPath = "C:/Windows/Fonts/msyh.ttc";
 
-} // namespace
-
 bool BuildDefaultXCUIEditorFontAtlas(::ImFontAtlas& atlas, ::ImFont*& outDefaultFont) {
     outDefaultFont = nullptr;
     atlas.Clear();
@@ -55,6 +53,19 @@ bool BuildDefaultXCUIEditorFontAtlas(::ImFontAtlas& atlas, ::ImFont*& outDefault
     return outDefaultFont != nullptr;
 }
 
+} // namespace
+
+bool ConfigureDefaultXCUIEditorFontsForCurrentContext() {
+    ImGuiIO& io = ImGui::GetIO();
+    ImFont* uiFont = nullptr;
+    if (!BuildDefaultXCUIEditorFontAtlas(*io.Fonts, uiFont)) {
+        return false;
+    }
+
+    io.FontDefault = uiFont;
+    return io.FontDefault != nullptr;
+}
+
 } // namespace XCUIBackend
 } // namespace Editor
 } // namespace XCEngine