feat(mobile): disable swipe back gesture when there is no back in header (#8876)

close AF-1663, AF-1756

- new global `ModalConfigContext`
- new logic to judge whether inside modal
- render `✕` for PageHeader back if inside modal
- only enable `NavigationGesture` when there is `<` in PageHeader

packages/frontend/apps/ios/src/modal-config.tsx

@@ -0,0 +1,28 @@
+import { ModalConfigContext } from '@affine/component';
+import { NavigationGestureService } from '@affine/core/mobile/modules/navigation-gesture';
+import { useService } from '@toeverything/infra';
+import { type PropsWithChildren, useCallback } from 'react';
+
+export const ModalConfigProvider = ({ children }: PropsWithChildren) => {
+  const navigationGesture = useService(NavigationGestureService);
+
+  const onOpenChange = useCallback(
+    (open: boolean) => {
+      const prev = navigationGesture.enabled$.value;
+      if (open && !prev) {
+        navigationGesture.setEnabled(false);
+        return () => {
+          navigationGesture.setEnabled(prev);
+        };
+      }
+      return;
+    },
+    [navigationGesture]
+  );
+
+  return (
+    <ModalConfigContext.Provider value={{ onOpenChange }}>
+      {children}
+    </ModalConfigContext.Provider>
+  );
+};