Card bulk operations, remove expand/collapse, graph color picker fix

- Bulk selection mode: Ctrl+Click or toggle button to enter, Escape to exit
- Shift+Click for range select, bottom toolbar with SVG icon action buttons
- All CardSections wired with bulk actions: Delete everywhere,
  Start/Stop for targets, Enable/Disable for automations
- Remove expand/collapse all buttons (no collapsible sections remain)
- Fix graph node color picker overlay persisting after outside click
- Add Icons section to frontend.md conventions
- Add trash2, listChecks, circleOff icons to icon system
- Backend: processing loop performance improvements (monotonic timestamps,
  deque-based FPS tracking)

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

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

@@ -68,7 +68,6 @@ import {
     showAddCSPTModal, editCSPT, closeCSPTModal, saveCSPT, deleteCSPT, cloneCSPT,
     csptAddFilterFromSelect, csptToggleFilterExpand, csptRemoveFilter, csptUpdateFilterOption,
     renderCSPTModalFilterList,
-    expandAllStreamSections, collapseAllStreamSections,
 } from './features/streams.js';
 import {
     createKCTargetCard, testKCTarget,
@@ -90,7 +89,6 @@ import {
     loadAutomations, openAutomationEditor, closeAutomationEditorModal,
     saveAutomationEditor, addAutomationCondition,
     toggleAutomationEnabled, cloneAutomation, deleteAutomation, copyWebhookUrl,
-    expandAllAutomationSections, collapseAllAutomationSections,
 } from './features/automations.js';
 import {
     openScenePresetCapture, editScenePreset, saveScenePreset, closeScenePresetEditor,
@@ -111,7 +109,6 @@ import {
     stopAllLedTargets, stopAllKCTargets,
     startTargetOverlay, stopTargetOverlay, deleteTarget,
     cloneTarget, toggleLedPreview,
-    expandAllTargetSections, collapseAllTargetSections,
     disconnectAllLedPreviewWS,
 } from './features/targets.js';
 
@@ -275,7 +272,6 @@ Object.assign(window, {
     // streams / capture templates / PP templates
     loadPictureSources,
     switchStreamTab,
-    expandAllStreamSections, collapseAllStreamSections,
     showAddTemplateModal,
     editTemplate,
     closeTemplateModal,
@@ -377,8 +373,6 @@ Object.assign(window, {
     cloneAutomation,
     deleteAutomation,
     copyWebhookUrl,
-    expandAllAutomationSections,
-    collapseAllAutomationSections,
 
     // scene presets
     openScenePresetCapture,
@@ -404,7 +398,6 @@ Object.assign(window, {
     // targets
     loadTargetsTab,
     switchTargetSubTab,
-    expandAllTargetSections, collapseAllTargetSections,
     showTargetEditor,
     closeTargetEditorModal,
     forceCloseTargetEditorModal,