feat: improve action button visibility with explicit styling and icon rendering

- Add explicit border and background colors to action buttons for better visibility
- Ensure Lucide icons are properly rendered in action buttons with deferred safeCreateIcons call
- Adjust badge margin to prevent overlap with action buttons
- Add z-index to action buttons to ensure proper layering

frontend/app.js

@@ -4749,7 +4749,8 @@
     button.className = "tree-item-action-btn";
     button.setAttribute("aria-label", "Afficher le menu d’actions");
     button.setAttribute("title", "Actions");
-    button.appendChild(icon("ellipsis", 16));
+    const iconEl = icon("ellipsis", 16);
+    button.appendChild(iconEl);
     button.addEventListener("click", (e) => {
       e.preventDefault();
       e.stopPropagation();
@@ -4757,6 +4758,10 @@
       ContextMenuManager.show(pos.x, pos.y, vault, path, type, isReadonly);
     });
     itemEl.appendChild(button);
+    // Ensure Lucide icons are rendered for the button
+    setTimeout(() => {
+      safeCreateIcons(button);
+    }, 0);
   }
 
   function attachTreeItemLongPress(itemEl, getMenuData) {