track fileIDs, not size for similar files group

mobile/apps/photos/lib/models/similar_files.dart

@@ -2,16 +2,23 @@ import "package:photos/models/file/file.dart";
 
 class SimilarFiles {
   final List<EnteFile> files;
-  final int totalSize;
+  final Set<int> fileIds;
   final double furthestDistance;
 
   SimilarFiles(
     this.files,
-    this.totalSize,
     this.furthestDistance,
-  );
+  )      : fileIds = files.map((file) => file.uploadedFileID!).toSet();
+
+  int get totalSize =>
+      files.fold(0, (sum, file) => sum + (file.fileSize ?? 0));
 
   @override
   String toString() =>
       'SimilarFiles(files: $files, size: $totalSize, distance: $furthestDistance)';
+
+  void removeFile(EnteFile file) {
+    files.remove(file);
+    fileIds.remove(file.uploadedFileID);
+  }
 }

mobile/apps/photos/lib/services/machine_learning/similar_images_service.dart

@@ -117,14 +117,11 @@ class SimilarImagesService {
       }
       if (similarFilesList.isNotEmpty) {
         similarFilesList.add(firstLoopFile);
-        int totalSize = 0;
         for (final file in similarFilesList) {
           alreadyUsedFileIDs.add(file.uploadedFileID!);
-          totalSize += file.fileSize ?? 0;
         }
         final similarFiles = SimilarFiles(
           similarFilesList,
-          totalSize,
           furthestDistance,
         );
         allSimilarFiles.add(similarFiles);