Replace all emoji icons with Lucide SVGs, add accent color picker

- Replace all emoji characters across WebUI with inline Lucide SVG icons
  for cross-platform consistency (icon paths in icon-paths.js)
- Add accent color picker popover with 9 preset colors + custom picker,
  persisted to localStorage, updates all CSS custom properties
- Remove subtab separator line for cleaner look
- Color badge icons with accent color for visual pop
- Remove processing badge from target cards
- Fix hardcoded #4CAF50 in FPS labels and active badges to use CSS vars
- Replace CSS content emoji (▶) with pure CSS triangle

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

server/src/wled_controller/static/css/patterns.css

@@ -54,6 +54,10 @@
     vertical-align: middle;
 }
 
+.stream-card-prop .icon {
+    color: var(--primary-text-color);
+}
+
 .stream-card-prop-full {
     max-width: 100%;
     word-break: break-all;
@@ -72,6 +76,10 @@
     color: #fff;
 }
 
+.stream-card-link:hover .icon {
+    color: #fff;
+}
+
 @keyframes cardHighlight {
     0%, 100% { box-shadow: none; }
     25%, 75% { box-shadow: 0 0 0 3px var(--primary-color), 0 0 20px rgba(var(--primary-rgb, 59, 130, 246), 0.3); }