Floating polish: visibility, resize, saved geometry, D-Bus, desktop entry

- VisibilityController: show on field focus, dismiss until next focus,
  manual show/hide/toggle overrides
- FloatingWindow: resize from the corner grip, clamp to screen
- WindowSettings: geometry per screen, debounced saves
- DBusControl: org.sloposk.Keyboard Show/Hide/Toggle for global shortcuts
- org.sloposk.keyboard.desktop so System Settings lists it as a virtual keyboard
- README with build/run/layout docs

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/CMakeLists.txt

@@ -17,6 +17,8 @@ qt_add_library(sloposk_core STATIC
     layout/LayoutRepository.h layout/LayoutRepository.cpp
     layout/KeyGeometry.h layout/KeyGeometry.cpp
     layout/LayoutModel.h layout/LayoutModel.cpp
+    window/VisibilityController.h window/VisibilityController.cpp
+    window/WindowSettings.h window/WindowSettings.cpp
 )
 
 # QML lives in the top-level qml/ dir; alias each file so the module sees it at its root.
@@ -26,6 +28,7 @@ set(SLOPOSK_QML_FILES
     Key.qml
     AlternatesPopup.qml
     DragHandle.qml
+    ResizeHandle.qml
     Theme.qml
 )
 list(TRANSFORM SLOPOSK_QML_FILES PREPEND ${PROJECT_SOURCE_DIR}/qml/ OUTPUT_VARIABLE sloposk_qml_paths)
@@ -59,7 +62,8 @@ target_link_libraries(sloposk_core PUBLIC Qt6::Quick PkgConfig::XKB)
 
 qt_add_executable(sloposk
     main.cpp
-    DevHooks.h DevHooks.cpp
+    app/DevHooks.h app/DevHooks.cpp
+    app/DBusControl.h app/DBusControl.cpp
     backend/InputMethodProtocol.h
     backend/KWinInputMethod.h backend/KWinInputMethod.cpp
     backend/KWinInputContext.h backend/KWinInputContext.cpp
@@ -76,9 +80,11 @@ set_source_files_properties(${CMAKE_CURRENT_BINARY_DIR}/qwayland-input-method-un
 target_link_libraries(sloposk PRIVATE
     sloposk_core
     sloposk_coreplugin
+    Qt6::DBus
     Qt6::WaylandClient
     LayerShellQt::Interface
     PkgConfig::WAYLAND
 )
 
 install(TARGETS sloposk)
+install(FILES ${PROJECT_SOURCE_DIR}/data/org.sloposk.keyboard.desktop DESTINATION ${CMAKE_INSTALL_DATADIR}/applications)