feat(exif): stamp RC_<ts> filenames + EXIF on capture and export

src/utils/nativeExport.ts

@@ -7,12 +7,12 @@
 // Deliberately does NOT import exportEngine or Skia: when the native path is
 // active the Skia engine must not even load.
 import RecipescamExport, { PhotoAdjust } from '../../modules/recipescam-export';
-import * as FileSystem from 'expo-file-system/legacy';
 import * as MediaLibrary from 'expo-media-library/legacy';
 import { Recipe, GPSInfo, FrameId, AspectRatio, ColorAdjustments } from '../types';
 import { getSkiaColorMatrix, applyExposureGain } from './colorUtils';
 import { getToneUniforms } from './toneShader';
 import { getCinemaUniforms } from './cinemaShader';
+import { nextPhotoPath, stampExifOnFile } from './photoMeta';
 
 export interface NativeExportResult {
   uri: string;
@@ -37,15 +37,15 @@ export interface NativeExportOptions {
   // module renders geo captions but has no text-watermark draw (ponytail: add
   // it when native parity with the Skia engine is completed).
   watermark?: { text: string; x: number; y: number } | null;
+  // Gallery filename + EXIF, same contract as ExportOptions.exported /
+  // .capturedAt: RC_<ts>_exported.jpg keeps the loaded photo's own EXIF.
+  exported?: boolean;
+  capturedAt?: number | null;
 }
 
 // The Kotlin module reads plain absolute paths, not file:// URIs.
 const stripScheme = (uri: string) => uri.replace(/^file:\/\//, '');
 
-// Unique filename per export (same cache-bust rationale as exportEngine: a fixed
-// path would serve stale <Image> cache entries).
-const nextExportFile = () => `${FileSystem.cacheDirectory}camrecipe_pro_export_${Date.now()}.jpg`;
-
 export async function processAndExportPhotoNative(
   sourceUri: string,
   recipe: Recipe,
@@ -99,9 +99,20 @@ export async function processAndExportPhotoNative(
       aspect,
     };
 
-    const exportFile = nextExportFile(); // file:// URI (cacheDirectory)
+    const exportFile = nextPhotoPath(options?.exported === true); // file:// URI (cacheDirectory)
     const dstPath = stripScheme(exportFile);
     await RecipescamExport.processPhotoAsync(stripScheme(sourceUri), dstPath, matrix, null, adjust);
+    // Same EXIF contract as the Skia engine (step 9c). ponytail: pixel
+    // dimensions are left out here — Kotlin knows the rendered size, JS does not.
+    await stampExifOnFile(
+      exportFile,
+      {
+        dateTime: options?.capturedAt ? new Date(options.capturedAt) : null,
+        gps: useGeotag && gpsInfo ? { latitude: gpsInfo.latitude, longitude: gpsInfo.longitude } : null,
+        dpi: options?.dpi ?? null,
+      },
+      sourceUri
+    );
 
     const mediaPermission = await MediaLibrary.requestPermissionsAsync();
     if (mediaPermission.granted) {