fix: add --surface-subtle token, restore info grouping, and apply theme-aware favorite color

- Add --surface-subtle (oklch 3% opacity) to replace rgba(0,0,0,0.03)
- Fix info items, creator-info, civitai-view, modal-send-btn, header-actions
  to use --surface-subtle instead of --surface-hover
- Keep true hover states on --surface-hover
- Use light #d4a017 / dark #ffc107 for --favorite-color based on theme
- Replace hardcoded #ffc107 and #d4a017 with var(--favorite-color)

static/css/components/modal/support-modal.css

@@ -258,7 +258,7 @@
     color: white; /* Icon color changes to white on hover */
 }
 
-/* 增强hover状态的视觉反馈 */
+/* Enhanced hover visual feedback */
 .social-link:hover,
 .update-link:hover,
 .folder-item:hover {