Add collapsible dashboard sections with localStorage persistence

Each dashboard section (Profiles, Running, Stopped) now has a chevron
toggle that collapses/expands the section content. Collapsed state is
persisted in localStorage so it survives page reloads and WebSocket
re-renders. Stop All button uses event.stopPropagation() to avoid
triggering the section toggle.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/src/wled_controller/static/js/app.js

@@ -37,6 +37,7 @@ import {
 import {
     loadDashboard, startDashboardWS, stopDashboardWS,
     dashboardToggleProfile, dashboardStartTarget, dashboardStopTarget, dashboardStopAll,
+    toggleDashboardSection,
 } from './features/dashboard.js';
 import {
     loadPictureSources, switchStreamTab,
@@ -151,6 +152,7 @@ Object.assign(window, {
     dashboardStartTarget,
     dashboardStopTarget,
     dashboardStopAll,
+    toggleDashboardSection,
 
     // streams / capture templates / PP templates
     loadPictureSources,