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/css/automations.css

@@ -27,9 +27,18 @@
     padding: 0 4px;
 }
 
-/* Automation condition pills need more room than the default 180px */
+/* Automation condition pills — constrain to card width */
+[data-automation-id] .card-meta {
+    display: flex;
+    flex-wrap: wrap;
+    gap: 4px;
+    min-width: 0;
+}
 [data-automation-id] .stream-card-prop {
-    max-width: 280px;
+    max-width: 100%;
+    overflow: hidden;
+    text-overflow: ellipsis;
+    white-space: nowrap;
 }
 
 /* Automation condition editor rows */