fix: Dropdown menus rendering outside SPA container

- Add getPortalContainer to DropdownMenuContent (like Dialog)
- Portal container created inside #woonoow-admin-app
- Copy theme class (light/dark) for proper CSS variable inheritance
- Fixes Add Section dropdown styling in Page Editor

admin-spa/src/components/ui/dropdown-menu.tsx

@@ -57,8 +57,33 @@ DropdownMenuSubContent.displayName =
 const DropdownMenuContent = React.forwardRef<
   React.ElementRef<typeof DropdownMenuPrimitive.Content>,
   React.ComponentPropsWithoutRef<typeof DropdownMenuPrimitive.Content>
->(({ className, sideOffset = 4, ...props }, ref) => (
-  <DropdownMenuPrimitive.Portal>
+>(({ className, sideOffset = 4, ...props }, ref) => {
+  // Get or create portal container inside the app for proper CSS scoping
+  const getPortalContainer = () => {
+    const appContainer = document.getElementById('woonoow-admin-app');
+    if (!appContainer) return document.body;
+
+    let portalRoot = document.getElementById('woonoow-dropdown-portal');
+    if (!portalRoot) {
+      portalRoot = document.createElement('div');
+      portalRoot.id = 'woonoow-dropdown-portal';
+      // Copy theme class from documentElement for proper CSS variable inheritance
+      const themeClass = document.documentElement.classList.contains('dark') ? 'dark' : 'light';
+      portalRoot.className = themeClass;
+      appContainer.appendChild(portalRoot);
+    } else {
+      // Update theme class in case it changed
+      const themeClass = document.documentElement.classList.contains('dark') ? 'dark' : 'light';
+      if (!portalRoot.classList.contains(themeClass)) {
+        portalRoot.classList.remove('light', 'dark');
+        portalRoot.classList.add(themeClass);
+      }
+    }
+    return portalRoot;
+  };
+
+  return (
+    <DropdownMenuPrimitive.Portal container={getPortalContainer()}>
       <DropdownMenuPrimitive.Content
         ref={ref}
         sideOffset={sideOffset}
@@ -70,7 +95,8 @@ const DropdownMenuContent = React.forwardRef<
         {...props}
       />
     </DropdownMenuPrimitive.Portal>
-))
+  );
+})
 DropdownMenuContent.displayName = DropdownMenuPrimitive.Content.displayName
 
 const DropdownMenuItem = React.forwardRef<