tests: remove legacy test tree

tests/UI/Core/integration/README.md

@@ -1,25 +0,0 @@
-# Core UI Integration Validation
-
-This directory contains the manual XCUI validation system for shared Core primitives.
-
-Structure:
-
-- `shared/`: shared host, native renderer, screenshot helper, scenario registry
-- `input/`: shared input validation category
-- `layout/`: shared layout validation category
-- `style/`: shared theme token and style resolution validation category
-- `text/`: shared UTF-8 text rendering and textInput focus marker validation category
-
-Rules:
-
-- One scenario directory maps to one executable.
-- Do not accumulate unrelated checks into one monolithic app.
-- Shared infrastructure belongs in `shared/`, not duplicated per scenario.
-- Screenshots are written only under the active CMake build directory.
-- The output root is the executable directory: `.../Debug/captures/<scenario>/`.
-
-Build:
-
-```bash
-cmake --build build --config Debug --target core_ui_integration_tests
-```