Zoom the FRAME preview instead of the photo, and save to DCIM/Camera

- FRAME tab now pinches the whole view (frame + photo + watermark) in both
  camera and library; one finger pans that view. Preview only: the exported
  file is identical at 1x and while the view is magnified.
- Watermark pinch/drag stay relative and keep priority while the WATERMARK
  row is open, so they still work after returning from the FRAME tab.
- Exports go through a native MediaStore insert into DCIM/Camera, falling
  back to expo-media-library when the native save fails.

src/utils/exportEngine.ts

@@ -11,6 +11,9 @@ import { drawFrameOnCanvas, polaroidLayout, POLAROID_CARD, POLAROID_WIN_W, wallf
 import { patchJpegDpi } from './jpegDpi';
 import { writeJpegExif } from './exifWrite';
 import { nextPhotoPath, readPhotoBytes, getDeviceIdentity } from './photoMeta';
+import RecipescamExport from '../../modules/recipescam-export';
+
+const stripScheme = (uri: string) => uri.replace(/^file:\/\//, '');
 import { applyPhotoRotation } from './skiaImage';
 
 export interface ExportResult {
@@ -746,6 +749,15 @@ export async function processAndExportPhoto(
     // viewer; the OS cache purge reclaims them eventually.
     const mediaPermission = await MediaLibrary.requestPermissionsAsync();
     if (mediaPermission.granted) {
+      // DCIM/Camera (stock camera location) first: expo-media-library can only
+      // reach DCIM (root) or Pictures/Camera, so the native module does the
+      // MediaStore insert. Falls back to the plain expo save if that fails.
+      try {
+        const assetId = await RecipescamExport.saveToCameraRollAsync(stripScheme(exportFile), 'image/jpeg');
+        if (assetId) return { uri: exportFile, savedToLibrary: true, assetId };
+      } catch (e) {
+        console.warn('Native DCIM/Camera save failed, falling back to MediaLibrary:', e);
+      }
       try {
         const asset = await MediaLibrary.createAssetAsync(exportFile);
         return { uri: exportFile, savedToLibrary: true, assetId: asset.id };