-`new_editor` now has an explicit two-step window compositor seam through `IWindowUICompositor` / `ImGuiWindowUICompositor`, layered on top of `IEditorHostCompositor` / `ImGuiHostCompositor`
- Build-system hardening for MSVC/PDB output paths has started in root CMake, `engine/CMakeLists.txt`, `new_editor/CMakeLists.txt`, and `tests/NewEditor/CMakeLists.txt`.
- Shared engine-side `UIDocumentScreenHost` now compiles `.xcui` / `.xctheme` screen documents into a runtime-facing document host path instead of leaving all document ownership in `new_editor`.
- Shared text-editing primitives now live under `engine/include/XCEngine/UI/Text` and `engine/src/UI/Text`, so UTF-8 caret movement, line splitting, and multiline navigation are no longer trapped inside `XCUI Demo`.
- Shared text-input controller/state now also lives under `engine/include/XCEngine/UI/Text` and `engine/src/UI/Text`, so character insertion, backspace/delete, submit, and multiline key handling no longer need to be reimplemented per host.
- Shared editor collection primitive classification and metric helpers now also live under `engine/include/XCEngine/UI/Widgets` and `engine/src/UI/Widgets`, covering the current `ScrollView` / `TreeView` / `ListView` / `PropertySection` / `FieldRow` prototype taxonomy.
- Shared single-selection state now also lives under `engine/include/XCEngine/UI/Widgets` and `engine/src/UI/Widgets` as `UISelectionModel`, so collection-style widget selection no longer has to stay private to `LayoutLab`.
- Shared expansion state now also lives under `engine/include/XCEngine/UI/Widgets` and `engine/src/UI/Widgets` as `UIExpansionModel`, so collapsible tree/property-style widget state no longer has to stay private to `LayoutLab`.
- Core regression coverage now includes `UIContext`, layout, style, runtime screen player/system, and real document-host tests through `core_ui_tests`.
- Minimal schema self-definition support is landed, including consistency checks for enum/document-only schema metadata, but schema-driven validation for `.xcui` / `.xctheme` instances is still not implemented.
- Common widget primitives are still incomplete: shared text-input presentation/composition on top of the new text controller, multi-selection/keyboard-navigation/virtualized collection state on top of the new editor-primitive helpers, and native image/source-rect level APIs.
- The main concrete progress here is that the retained-mode demo runtime now supports a real `TextField` input path with UTF-8 text entry and backspace handling.
- The demo runtime has moved past single-line input: multiline `TextArea` behavior is now covered in the sandbox testbed.
- Engine-side runtime ownership is no longer zero: `UIScreenPlayer`, `UIDocumentScreenHost`, and `UISystem` now define a shared runtime contract for loading a screen document, ticking it with input, and collecting `UI::UIDrawData`.
-`UISystem` now supports layered screen composition semantics: stacked screen players, top-interactive input routing, and modal layers that block lower screens.
-`UIScreenStackController::ReplaceTop` now preserves the previous top screen if the replacement screen fails to load, so runtime menu flows do not silently drop their active layer on bad assets.
-`SceneRuntime` now owns a dedicated `UISceneRuntimeContext`, so game/runtime code has a first-class place to configure viewport/focus, queue `UIInputEvent`s, drive `UISystem` each `Update`, and inspect the latest UI frame result.
- Runtime UI is now wired into `SceneRuntime`, but render submission is still limited to producing `UIDrawData`; there is no game-view/runtime presenter path that automatically draws those frames yet.
- Hosted preview surface descriptors now stay on XCUI-owned value types (`UITextureHandle`, `UIPoint`, `UIRect`) instead of exposing ImGui texture/UV types through the generic preview contract.
-`XCUI Demo` now covers both single-line and multiline text authoring behavior, including click caret placement, delete/backspace, tab indentation, and optional text-area line numbers.
-`LayoutLab` now consumes the shared `UIEditorCollectionPrimitives` helper layer for collection-widget tag classification, clipping flags, and default metric resolution instead of keeping that taxonomy private to the sandbox runtime.
-`LayoutLab` now also consumes the shared `UISelectionModel` for click-selection persistence across collection-style widgets, and the diagnostics panel now exposes both hovered and selected element ids.
-`LayoutLab` now also consumes the shared `UIExpansionModel` for tree expansion and property-section collapse, with reserved property headers, disclosure glyphs, and persisted click-toggle behavior in the sandbox runtime.
-`Application` no longer owns the ImGui backend directly; window presentation now routes through `IWindowUICompositor` with an `ImGuiWindowUICompositor` implementation, which currently delegates to `IEditorHostCompositor` / `ImGuiHostCompositor`.
- The generic hosted-preview presenter contract no longer owns `ImGuiTransitionBackend`; the ImGui presenter now sits in a separate `ImGuiXCUIHostedPreviewPresenter` header while the native queue/surface registry remains XCUI-generic.
- The generic hosted-preview frame contract no longer carries an ImGui draw-list pointer; the legacy ImGui presenter resolves its inline draw target from the active ImGui window context instead of pushing that type through the XCUI contract.
- Editor-specialized widgets are still incomplete at the shared-module level: the authored prototypes exist, but virtualization, multi-selection/keyboard-navigation state, command routing, property editing models, toolbar/menu chrome, and icon-atlas widgets are not yet extracted into reusable XCUI modules.
- Common-core `UITextInputController` extraction now owns per-field text state, character insertion, enter-submit, and multiline keyboard editing behavior with dedicated `core_ui_tests` coverage.
- Common-core `UIEditorCollectionPrimitives` extraction now owns the editor collection tag taxonomy and default metric resolution used by current `LayoutLab` widget prototypes, with dedicated `core_ui_tests` coverage.
- Common-core `UISelectionModel` extraction now owns reusable single-selection state for collection-style widgets, with dedicated `core_ui_tests` coverage.
- Common-core `UIExpansionModel` extraction now owns reusable expansion/collapse state for tree/property-style widgets, with dedicated `core_ui_tests` coverage.
- LayoutLab click-selection now persists through the shared `UISelectionModel`, including selected-state diagnostics and reusable visual selection feedback on cards, collection rows, and field rows.
- LayoutLab tree expansion and property-section collapse now persist through the shared `UIExpansionModel`, including reserved property headers, disclosure glyphs, and runtime coverage for collapsed/expanded visibility.
- The window-level XCUI compositor seam now also has a dedicated regression target around `ImGuiWindowUICompositor`, covering initialization, render-frame ordering, Win32 message forwarding, texture registration forwarding, and shutdown safety.
-`SceneRuntime` layered XCUI routing now has dedicated regression coverage for:
- top-interactive layer input ownership
- blocking/modal layer suppression of lower layers
- hidden top-layer pass-through back to visible underlying layers
- Shared `UITextInputController` coverage now includes more caret-boundary / modifier branches; the remaining `Delete` distinction stays blocked on `KeyCode::Delete` and `KeyCode::Backspace` still sharing the same enum value.
- Window compositor texture registration now also flows back into `Application` as XCUI-owned `UITextureRegistration` / `UITextureHandle` data instead of exposing raw `ImTextureID` there.
-`LayoutLab` now resolves editor collection widget taxonomy and metrics through shared `UIEditorCollectionPrimitives` helpers instead of duplicating the same tag and metric rules inside the sandbox runtime.
-`new_editor` panel/shell diagnostics improvements for hosted preview state.
- XCUI asset document loading changed to prefer direct source compilation before `ResourceManager` fallback for the sandbox path, fixing the LayoutLab crash.
- Editor widget coverage is still prototype-driven inside `LayoutLab`; it has not yet been promoted into a full reusable shared widget/runtime layer with command routing, virtualization, and property-edit transactions.
1. Expand runtime/game-layer ownership from the current `SceneRuntime` UI context into scene-declared HUD/menu bootstrapping, draw submission, and higher-level runtime UI policies.
2. Promote the current editor-facing widget prototypes out of authored `LayoutLab` content and into reusable XCUI widget/runtime modules, then continue with toolbar/menu and more native shell-owned chrome.
3. Add a native XCUI host compositor on the existing window-level compositor seam so `new_editor` can present without going through ImGui-owned draw data.
4. Reduce remaining ImGui leakage in hosted preview surfaces and panel contracts now that the compositor seam is in place.
