refactor(new_editor): tighten app dependency boundaries

new_editor/app/Host/TextureHost.h

@@ -0,0 +1,28 @@
+#pragma once
+
+#include <XCEngine/UI/Types.h>
+
+#include <cstddef>
+#include <cstdint>
+#include <filesystem>
+#include <string>
+
+namespace XCEngine::UI::Editor::Host {
+
+class TextureHost {
+public:
+    virtual ~TextureHost() = default;
+
+    virtual bool LoadTextureFromFile(
+        const std::filesystem::path& path,
+        ::XCEngine::UI::UITextureHandle& outTexture,
+        std::string& outError) = 0;
+    virtual bool LoadTextureFromMemory(
+        const std::uint8_t* data,
+        std::size_t size,
+        ::XCEngine::UI::UITextureHandle& outTexture,
+        std::string& outError) = 0;
+    virtual void ReleaseTexture(::XCEngine::UI::UITextureHandle& texture) = 0;
+};
+
+} // namespace XCEngine::UI::Editor::Host