Fix window chrome positioning on Sway

Improves focused-window geometry so chrome placement stays stable across workspaces and floating containers. WindowService now exposes focused workspace X/Y, resolves workspace by name, and publishes those offsets with focused geometry. The Sway backend now tracks the active floating frame through recursion and consistently derives frame/deco/content rects from that frame. QML chrome placement was updated to use workspace-relative coordinates and simpler direct margins (removing interpolation behaviors), with safer title-bar height handling for vertical centering.

core/windows/WorkspaceModel.cpp

@@ -82,3 +82,14 @@ const WorkspaceInfo *WorkspaceModel::focusedWorkspace() const
     }
     return nullptr;
 }
+
+const WorkspaceInfo *WorkspaceModel::workspaceByName(const QString &name) const
+{
+    if (name.isEmpty())
+        return nullptr;
+    for (const WorkspaceInfo &workspace : m_workspaces) {
+        if (workspace.name == name)
+            return &workspace;
+    }
+    return nullptr;
+}