Fix item pane section button icons in light and dark themes.

Wire stroke context properties for Lucide SVG toolbar icons and set light/dark icon URLs on open-in-window and adaptive-height buttons.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/modules/ui/readerPane.ts

@@ -3,6 +3,7 @@ import { getLocaleID, getString } from "../../utils/locale";
 import { ChatView } from "./chatView";
 import {
   applyAdaptiveHeight,
+  applyItemPaneSectionButtonIcons,
   buildItemPaneSectionButtons,
   onItemPaneSectionToggle,
   prepareItemPaneBody,
@@ -62,6 +63,7 @@ export function registerChatPane() {
       views.set(body, view);
       await view.mount();
       applyAdaptiveHeight(body, "chat");
+      applyItemPaneSectionButtonIcons(body);
       const section = body.closest("collapsible-section");
       if (section?.hasAttribute("open")) {
         refreshSectionOpenHeight(body);