fix: replace only missing uploads with dummy document

src/Service/Upload/UploadHandler.php

@@ -164,24 +164,40 @@ class UploadHandler
     }
 
     /**
-     * Returns the upload file path, substituting the stand-in document while the
-     * upload_replacement feature is on. Use this for read-only access (downloads, email
-     * attachments); getUploadFilepath() stays the real location and is what writes target.
+     * Returns the upload file path, falling back to the stand-in document when the real file is
+     * missing and the upload_replacement feature is on.
+     *
+     * Environments other than prod run on anonymized copies of the production database but never
+     * carry over the uploaded files, so most rows point at a file that is not there. The stand-in
+     * fills exactly that gap: a file that is present - one uploaded while testing - is always
+     * served as it is, which is what keeps the upload flow exercisable.
+     *
+     * Use this for read-only access (downloads, email attachments); getUploadFilepath() stays the
+     * real location and is what writes target.
      */
     public function getResolvedUploadFilepath(Upload $upload): string
     {
+        $originalPath = $this->getUploadFilepath($upload);
+
+        if (true === file_exists($originalPath)) {
+            return $originalPath;
+        }
+
         if (false === $this->featureManager->isActive('upload_replacement')) {
-            return $this->getUploadFilepath($upload);
+            return $originalPath;
         }
 
         $replacementPath = sprintf('%s/%s', $this->projectDir, $this->uploadReplacementFile);
 
         if (false === file_exists($replacementPath)) {
-            // Falling back to the real document here is what made the old behaviour opaque: the
-            // feature would look active and quietly serve the genuine file instead.
             throw new \RuntimeException('Upload replacement file not found at '.$replacementPath);
         }
 
+        $this->logger->info('Serving upload replacement', [
+            'file_id' => $upload->getId(),
+            'missing_path' => $originalPath,
+        ]);
+
         return $replacementPath;
     }