Add graph icon grid, search-to-graph nav, overlay on CSS cards, fix clipboard copy

- Convert graph editor add-entity menu to showTypePicker icon grid with SVG icons
- Add CSPT to graph add-entity picker and ALL_CACHES watcher
- Add graphNavigateToNode() — command palette navigates to graph node when graph tab active
- Add CSPT entities to global search palette results
- Add overlay toggle button on picture-based CSS cards (toggleCSSOverlay)
- Fix clipboard copy on non-HTTPS (LAN) with execCommand fallback for all copy functions
- Fix notification bell button vertical centering in test preview strip canvas
- Add overlay.toggle, search.group.cspt i18n keys (en/ru/zh)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

server/src/wled_controller/static/js/features/devices.js

@@ -635,10 +635,15 @@ async function _populateSettingsSerialPorts(currentUrl) {
 
 export function copyWsUrl() {
     const input = document.getElementById('settings-ws-url');
-    if (input && input.value) {
+    if (!input || !input.value) return;
+    if (navigator.clipboard && window.isSecureContext) {
         navigator.clipboard.writeText(input.value).then(() => {
             showToast(t('settings.copied') || 'Copied!', 'success');
         });
+    } else {
+        input.select();
+        document.execCommand('copy');
+        showToast(t('settings.copied') || 'Copied!', 'success');
     }
 }