fix(uploads): apply RAW extraction in the actual async ingest path (codex review of #833)

The RAW/DNG extraction was only wired into processUploadedPhotos() (the
synchronous path), but real uploads queue to 'pending' and are handled by the
background worker → processPhoto(), which generated the thumbnail + dimensions
directly from the DNG (both fail) and then marked the photo 'complete' — success
with no thumbnail. Wire withProcessableImage() into processPhoto() (the live
path) and into photoReplacementService.replacePhoto() (replace-by-name), so all
three ingest paths extract the embedded JPEG preview for RAW.

Updates the processPhoto test's imageProcessor mock with the new
withProcessableImage dependency (pass-through for ordinary images).

backend/__tests__/services/photoProcessor.processPhoto.test.js

@@ -75,6 +75,13 @@ jest.mock('../../src/services/imageProcessor', () => {
     withLocalCopy: jest.fn(async (key, fn) =>
       fn(`/tmp/local-copy-${require('path').basename(key)}`)
     ),
+    // Pass-through for ordinary (non-RAW) images: returns the path unchanged
+    // with a no-op cleanup, matching the real helper's behaviour for jpg/png.
+    withProcessableImage: jest.fn(async (localPath) => ({
+      path: localPath,
+      outputBasename: undefined,
+      cleanup: () => {},
+    })),
   };
 });