[feat] Add CSS LOD classes for Vue node rendering optimization

- Add lg-node--lod-full, lg-node--lod-reduced, lg-node--lod-minimal classes
- Reduced detail level uses smaller fonts and reduced padding
- Minimal detail level hides controls and uses compact header
- Smooth transitions between LOD levels to prevent jarring changes
- User select disabled on nodes to prevent text selection issues

These classes enable progressive detail reduction at different zoom levels for better performance.

src/assets/css/style.css

@@ -679,6 +679,11 @@ audio.comfy-audio.empty-audio-widget {
 /* Smooth transitions between LOD levels */
 .lg-node {
   transition: min-height 0.2s ease;
+  /* Disable text selection on all nodes */
+  user-select: none;
+  -webkit-user-select: none;
+  -moz-user-select: none;
+  -ms-user-select: none;
 }
 
 .lg-node .lg-slot,