Add floating traffic-light window chrome

Introduces a dedicated layer-shell `WindowChromeSurface` that renders macOS-style traffic-light controls over the focused Sway window titlebar, replacing the old top-bar window controls. Adds theme tokens and a reusable `TrafficLightButton` component, updates shell QML/CMake wiring, and adjusts Sway titlebar padding/title format so window titles do not overlap the overlay. Window tracking was extended with focused-window geometry/deco/fullscreen properties plus backend refresh support so the chrome follows window movement and state changes in near real time.

core/windows/backends/sway/SwayWindowBackend.hpp

@@ -32,6 +32,7 @@ public:
     bool resizeWindow(qint64 windowId, int width, int height) override;
     bool snapWindow(qint64 windowId, SnapEdge edge) override;
     bool switchWorkspace(const QString &workspaceId) override;
+    bool updateFocusedGeometry() override;
 
 private:
     void tryConnect();