Fix sidebar toggle button not responding after collapse

toggle-sidebar action was only in the DashboardView inline script,
not in dashboard.js where toggleSidebar() is defined. Move it into
the dashboard.js event delegation switch so it's guaranteed to fire.
Also fix beta webhook: was using a different secret than production
so Gitea pushes to development never triggered the beta deploy.

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

assets/js/dashboard.js

@@ -226,6 +226,10 @@ document.addEventListener('DOMContentLoaded', function() {
             case 'open-advanced-search':
                 if (typeof openAdvancedSearch === 'function') openAdvancedSearch();
                 break;
+            // Sidebar toggle
+            case 'toggle-sidebar':
+                toggleSidebar();
+                break;
             // Mobile navigation
             case 'open-mobile-sidebar':
                 if (typeof openMobileSidebar === 'function') openMobileSidebar();