Separate tree nodes into independent panels, remove graph local search, UI improvements

- Split Sources tab: raw/raw_templates, processed/proc_templates each get own panel
- Split Targets tab: led-devices, led-targets, kc-targets, kc-patterns each get own panel
- Remove graph local search — search button and / key open global command palette
- Add graphNavigateToNode for command palette → graph node navigation
- Add tree group expand/collapse animation (max-height + opacity transition)
- Make tree group headers visually distinct (smaller, uppercase, left border on children)
- Make CardSection collapse opt-in via collapsible flag (disabled by default)
- Move filter textbox next to section title (remove margin-left: auto)
- Fix notification bell button vertical centering in test preview
- Fix clipboard copy on non-HTTPS with execCommand fallback
- Add overlay toggle button on picture-based CSS cards
- Add CSPT to graph add-entity picker and global search
- Update all cross-link navigation paths for new panel keys
- Add i18n keys for new tree groups and search groups (en/ru/zh)

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

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

@@ -163,7 +163,7 @@ import {
 
 // Layer 5.5: graph editor
 import {
-    loadGraphEditor, openGraphSearch, closeGraphSearch,
+    loadGraphEditor,
     toggleGraphLegend, toggleGraphMinimap, toggleGraphFilter,
     graphFitAll, graphZoomIn, graphZoomOut, graphRelayout,
     graphToggleFullscreen, graphAddEntity,
@@ -481,8 +481,6 @@ Object.assign(window, {
 
     // graph editor
     loadGraphEditor,
-    openGraphSearch,
-    closeGraphSearch,
     toggleGraphLegend,
     toggleGraphMinimap,
     toggleGraphFilter,