fix: guard hideMenuIfNotFrozen against undefined view state (#2694) (#2699)

When the EditorView is re-created (e.g. toggling editable) while the
side menu is visible, a queued floating-ui scroll callback can fire
after view.state has been cleared, causing a TypeError. Use optional
chaining so the early return covers that case.

Author: YousefED

packages/core/src/extensions/SideMenu/SideMenu.ts

@@ -785,8 +785,8 @@ export const SideMenuExtension = createExtension(({ editor }) => {
      * interfering with open submenus.
      */
     hideMenuIfNotFrozen() {
-      if (!view!.menuFrozen && view!.state!.show) {
-        view!.state!.show = false;
+      if (!view!.menuFrozen && view!.state?.show) {
+        view!.state.show = false;
         view!.emitUpdate(view!.state!);
       }
     },