fix: reveal Liang portraits beneath Windows desktop frame

lib/client.js

@@ -300,6 +300,13 @@ body[data-liang-skin="on"] > #root {
   background: transparent !important;
 }
 
+/* Windows paints the sidebar fill across the host frame, covering the portrait.
+   Match macOS's transparent frame while keeping the sidebar, caption, and
+   conversation surfaces painted by their own host rules. */
+html[data-windows-titlebar] body[data-liang-skin="on"] #root [class*="_frame"]:has(> [class*="_centerCol"]) {
+  background: transparent !important;
+}
+
 body[data-liang-skin="on"] button,
 body[data-liang-skin="on"] input,
 body[data-liang-skin="on"] textarea {