Advance redbear-full Wayland, greeter, and Qt integration

Consolidate the active desktop path around redbear-full while landing the greeter/session stack and the runtime fixes needed to keep Wayland and KWin bring-up moving forward.

local/recipes/system/redbear-greeter/source/ui/CMakeLists.txt

@@ -0,0 +1,29 @@
+cmake_minimum_required(VERSION 3.20)
+project(redbear-greeter-ui LANGUAGES CXX)
+
+set(CMAKE_AUTOMOC ON)
+set(CMAKE_AUTORCC ON)
+set(CMAKE_CXX_STANDARD 20)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+find_package(Qt6 REQUIRED COMPONENTS Core Gui Qml Quick QuickControls2)
+
+qt_add_executable(redbear-greeter-ui
+    main.cpp
+    greeter_backend.cpp
+    greeter_backend.h
+    resources.qrc
+)
+
+target_compile_options(redbear-greeter-ui PRIVATE -fcf-protection=none)
+target_link_options(redbear-greeter-ui PRIVATE -fcf-protection=none)
+
+target_link_libraries(redbear-greeter-ui PRIVATE
+    Qt6::Core
+    Qt6::Gui
+    Qt6::Qml
+    Qt6::Quick
+    Qt6::QuickControls2
+)
+
+install(TARGETS redbear-greeter-ui RUNTIME DESTINATION bin)