Add editor tree view widget contract

tests/UI/Editor/integration/README.md

@@ -23,6 +23,7 @@ Layout:
 - `shell/context_menu_basic/`: context menu root/submenu/dismiss/dispatch only
 - `shell/panel_frame_basic/`: panel frame layout/state/hit-test only
 - `shell/status_bar_basic/`: status bar slot/segment/hit-test only
+- `shell/tree_view_basic/`: TreeView row layout, indent, disclosure, selection, focus, hit-test only
 - `shell/tab_strip_basic/`: tab strip layout/state/hit-test/close/navigation only
 - `shell/viewport_slot_basic/`: viewport slot chrome/surface/status only
 - `shell/viewport_shell_basic/`: viewport shell request/state compose only
@@ -81,6 +82,11 @@ Scenarios:
   Executable: `XCUIEditorStatusBarBasicValidation.exe`
   Scope: status bar slot layout, hover/active segment hit target, separator layout only
 
+- `editor.shell.tree_view_basic`
+  Build target: `editor_ui_tree_view_basic_validation`
+  Executable: `XCUIEditorTreeViewBasicValidation.exe`
+  Scope: TreeView 基础控件验证；只检查行缩进、disclosure 展开/折叠、selection、hover/focus 和 hit-test，不涉及业务面板
+
 - `editor.shell.tab_strip_basic`
   Build target: `editor_ui_tab_strip_basic_validation`
   Executable: `XCUIEditorTabStripBasicValidation.exe`
@@ -171,6 +177,9 @@ Selected controls:
 - `shell/status_bar_basic/`
   Move the mouse across leading/trailing segments, click interactive segments, toggle focus/active, press `F12`.
 
+- `shell/tree_view_basic/`
+  先看顶部中文说明“这个测试在验证什么功能”，再点击 disclosure 和树节点行，检查 `Hover / Focused / Selected / Expanded / Visible / Result`，按 `重置`、`截图(F12)` 或直接按 `F12`。
+
 - `shell/tab_strip_basic/`
   Click `Document A / B / C`, click `X` on closable tabs, click content to focus, press `Left / Right / Home / End`, press `Reset`, press `F12`.