fix(registry): set floating toolbar placement to bottom on mobile to prevent overlap (#4619)

On mobile screens (iOS Safari / Android Chrome), native selection context menus pop up
above text selection. FloatingToolbar defaulting to placement: 'top' caused direct overlap.

Fix:
- Use useIsMobile hook in FloatingToolbar (floating-toolbar.tsx) to set placement: 'bottom' on mobile viewports.
- Update fallbackPlacements to prioritize bottom placements on mobile.
- Add patch changeset for www registry UI.

Closes #4619

Author: SamarthNimangre

.changeset/fix-floating-toolbar-mobile-placement-overlap.md

@@ -0,0 +1,5 @@
+---
+"www": patch
+---
+
+Fix `FloatingToolbar` overlapping with native mobile text selection context menus on mobile devices. Uses `useIsMobile` to set `placement: 'bottom'` on mobile viewports so custom floating toolbars render below selection instead of colliding with native mobile context menus.

apps/www/src/registry/ui/floating-toolbar.tsx

@@ -17,6 +17,7 @@ import {
   usePluginOption,
 } from 'platejs/react';
 
+import { useIsMobile } from '@/hooks/use-mobile';
 import { cn } from '@/lib/utils';
 
 import { Toolbar } from './toolbar';
@@ -29,6 +30,7 @@ export function FloatingToolbar({
 }: React.ComponentProps<typeof Toolbar> & {
   state?: FloatingToolbarState;
 }) {
+  const isMobile = useIsMobile();
   const editorId = useEditorId();
   const focusedEditorId = useEventEditorValue('focus');
   const isFloatingLinkOpen = !!usePluginOption({ key: KEYS.link }, 'mode');
@@ -43,16 +45,23 @@ export function FloatingToolbar({
       middleware: [
         offset(12),
         flip({
-          fallbackPlacements: [
-            'top-start',
-            'top-end',
-            'bottom-start',
-            'bottom-end',
-          ],
+          fallbackPlacements: isMobile
+            ? [
+                'bottom-start',
+                'bottom-end',
+                'top-start',
+                'top-end',
+              ]
+            : [
+                'top-start',
+                'top-end',
+                'bottom-start',
+                'bottom-end',
+              ],
           padding: 12,
         }),
       ],
-      placement: 'top',
+      placement: isMobile ? 'bottom' : 'top',
       ...state?.floatingOptions,
     },
   });